OF MIND AND BODY, ARE DEMONSTRATED

                               by Rene Descartes

                        translated by John Veitch, LL.D.

                         OF THEOLOGY OF PARIS 

  GENTLEMEN,- The motive which impels me to present this treatise to    
you is so reasonable, and, when you shall learn its design, I am    
confident that you also will consider that there is ground so valid 
for your taking it under your protection, that I can in no way  
better recommend it to you than by briefly stating the end which I  
proposed to myself in it. I have always been of opinion that the two    
questions respecting God and the soul were the chief of those that  
ought to be determined by help of philosophy rather than of 
theology; for although to us, the faithful, it be sufficient to hold    
as matters of faith, that the human soul does not perish with the   
body, and that God exists, it yet assuredly seems impossible ever to    
persuade infidels of the reality of any religion, or almost even any    
moral virtue, unless, first of all, those two things be proved to them  
by natural reason. And since in this life there are frequently greater  
rewards held out to vice than to virtue, few would prefer the right to  
the useful, if they were restrained neither by the fear of God nor the  
expectation of another life; and although it is quite true that the 
existence of God is to be believed since it is taught in the sacred 
Scriptures, and that, on the other hand, the sacred Scriptures are  
to be believed because they come from God (for since faith is a gift    
of God, the same Being who bestows grace to enable us to believe other  
things, can likewise impart of it to enable us to believe his own   
existence), nevertheless, this cannot be submitted to infidels, who 
would consider that the reasoning proceeded in a circle. And,   
indeed, I have observed that you, with all the other theologians,   
not only affirmed the sufficiency of natural reason for the proof of    
the existence of God, but also, that it may be inferred from sacred 
Scripture, that the knowledge of God is much clearer than of many   
created things, and that it is really so easy of acquisition as to  
leave those who do not possess it blame-worthy. This is manifest    
from these words of the Book of Wisdom, chap. xiii., where it is said,  
Howbeit they are not to be excused; for if their understanding was so  
great that they could discern the world and the creatures, why did  
they not rather find out the Lord thereof? * And in Romans, chap. i.,  
it is said that they are ®without excuse; and again, in the same   
place, by these words,-That which may be known of God is manifest in  
them- we seem to be admonished that all which can be known of God may  
be made manifest by reasons obtained from no other source than the  
inspection of our own minds. I have, therefore, thought that it 
would not be unbecoming in me to inquire how and by what way,   
without going out of ourselves, God may be more easily and certainly    
known than the things of the world.   

  And as regards the soul, although many have judged that its nature    
could not be easily discovered, and some have even ventured to say  
that human reason led to the conclusion that it perished with the   
body, and that the contrary opinion could be held through faith alone;  
nevertheless, since the Lateran Council, held under Leo X. (in session  
viii.), condemns these, and expressly enjoins Christian philosophers    
to refute their arguments, and establish the truth according to 
their ability, I have ventured to attempt it in this work. Moreover, I  
am aware that most of the irreligious deny the existence of God, and    
the distinctness of the human soul from the body, for no other  
reason than because these points, as they allege, have never as yet 
been demonstrated. Now, although I am by no means of their opinion, 
but, on the contrary, hold that almost all the proofs which have    
been adduced on these questions by great men, possess, when rightly 
understood, the force of demonstrations, and that it is next to 
impossible to discover new, yet there is, I apprehend, no more  
useful service to be performed in philosophy, than if some one were,    
once for all, carefully to seek out the best of these reasons, and  
expound them so accurately and clearly that, for the future, it 
might be manifest to all that they are real demonstrations. And 
finally, since many persons were greatly desirous of this, who knew 
that I had cultivated a certain method of resolving all kinds of    
difficulties in the sciences, which is not indeed new (there being  
nothing older than truth), but of which they were aware I had made  
successful use in other instances, I judged it to be my duty to make    
trial of it also on the present matter. 
  Now the sum of what I have been able to accomplish on the subject is  
contained in this treatise. Not that I here essayed to collect all the  
diverse reasons which might be adduced as proofs on this subject,   
for this does not seem to be necessary, unless on matters where no one  
proof of adequate certainty is to be had; but I treated the first   
and chief alone in such a manner that I should venture now to   
propose them as demonstrations of the highest certainty and 
evidence. And I will also add that they are such as to lead me to   
think that there is no way open to the mind of man by which proofs  
superior to them can ever be discovered; for the importance of the  
subject, and the glory of God, to which all this relates, constrain me  
to speak here somewhat more freely of myself than I have been   
accustomed to do. Nevertheless, whatever certitude and evidence I   
may find in these demonstrations, I cannot therefore persuade myself    
that they are level to the comprehension of all. But just as in 
geometry there are many of the demonstrations of Archimedes,    
Apollonius, Pappus, and others, which, though received by all as    
evident even and certain (because indeed they manifestly contain    
nothing which, considered by itself, it is not very easy to 
understand, and no consequents that are inaccurately related to 
their antecedents), are nevertheless understood by a very limited   
number, because they are somewhat long, and demand the whole attention  
of the reader: so in the same way, although I consider the  
demonstrations of which I here make use, to be equal or even    
superior to the geometrical in certitude and evidence, I am afraid, 
nevertheless, that they will not be adequately understood by many,  
as well because they also are somewhat long and involved, as chiefly    
because they require the mind to be entirely free from prejudice,   
and able with ease to detach itself from the commerce of the senses.    
And, to speak the truth, the ability for metaphysical studies is    
less general than for those of geometry. And, besides, there is 
still this difference that, as in geometry, all are persuaded that  
nothing is usually advanced of which there is not a certain 
demonstration, those but partially versed in it err more frequently in  
assenting to what is false, from a desire of seeming to understand it,  
than in denying what is true. In philosophy, on the other hand, 
where it is believed that all is doubtful, few sincerely give   
themselves to the search after truth, and by far the greater number 
seek the reputation of bold thinkers by audaciously impugning such  
truths as are of the greatest moment.   
  Hence it is that, whatever force my reasonings may possess, yet   
because they belong to philosophy, I do not expect they will have much  
effect on the minds of men, unless you extend to them your patronage    
and approval. But since your faculty is held in so great esteem by  
all, and since the name of SORBONNE is of such authority, that not  
only in matters of faith, but even also in what regards human   
philosophy, has the judgment of no other society, after the sacred  
councils, received so great deference, it being the universal   
conviction that it is impossible elsewhere to find greater  
perspicacity and solidity, or greater wisdom and integrity in giving    
judgment, I doubt not,- if you but condescend to pay so much regard to  
this treatise as to be willing, in the first place, to correct it   
(for, mindful not only of my humanity, but chiefly also of my   
ignorance, I do not affirm that it is free from errors); in the second  
place, to supply what is wanting in it, to perfect what is incomplete,  
and to give more ample illustration where it is demanded, or at 
least to indicate these defects to myself that I may endeavour to   
remedy them; and, finally, when the reasonings contained in it, by  
which the existence of God and the distinction of the human soul    
from the body are established, shall have been brought to such  
degree of perspicuity as to be esteemed exact demonstrations, of which  
I am assured they admit, if you condescend to accord them the   
authority of your approbation, and render a public testimony of 
their truth and certainty,- I doubt not, I say, but that    
henceforward all the errors which have ever been entertained on 
these questions will very soon be effaced from the minds of men. For    
truth itself will readily lead the remainder of the ingenious and   
the learned to subscribe to your judgment; and your authority will  
cause the atheists, who are in general sciolists rather than ingenious  
or learned, to lay aside the spirit of contradiction, and lead them,    
perhaps, to do battle in their own persons for reasonings which they    
find considered demonstrations by all men of genius, lest they  
should seem not to understand them; and, finally, the rest of   
mankind will readily trust to so many testimonies, and there will no    
longer be any one who will venture to doubt either the existence of 
God or the real distinction of mind and body. It is for you, in your    
singular wisdom, to judge of the importance of the establishment of 
such beliefs [who are cognisant of the disorders which doubt of 
these truths produces]. * But it would not here become me to commend    
at greater length the cause of God and religion to you, who have    
always proved the strongest support of the Catholic Church.   
  * The square brackets, here and throughout the volume, are used to  
mark additions to the original of the revised French translation.   

                        PREFACE TO THE READER 

  I HAVE already slightly touched upon the questions respecting the 
existence of God and the nature of the human soul, in the Discourse    
on the Method of rightly conducting the Reason, and seeking truth in    
the Sciences, published in French in the year 1637; not, however,  
with the design of there treating of them fully, but only, as it were,  
in passing, that I might learn from the judgments of my readers in  
what way I should afterwards handle them: for these questions appeared  
to me to be of such moment as to be worthy of being considered more 
than once, and the path which I follow in discussing them is so little  
trodden, and so remote from the ordinary route, that I thought it   
would not be expedient to illustrate it at greater length in French,    
and in a discourse that might be read by all, lest even the more    
feeble minds should believe that this path might be entered upon by 
  But, as in the discourse on Method, I had requested all who might 
find aught meriting censure in my writings, to do me the favour of  
pointing it out to me, I may state that no objections worthy of remark  
have been alleged against what I then said on these questions,  
except two, to which I will here briefly reply, before undertaking  
their more detailed discussion. 
  The first objection is that though, while the human mind reflects on  
itself, it does not perceive that it is any other than a thinking   
thing, it does not follow that its nature or essence consists only  
in its being a thing which thinks; so that the word only shall    
exclude all other things which might also perhaps be said to pertain    
to the nature of the mind.  
  To this objection I reply, that it was not my intention in that   
place to exclude these according to the order of truth in the matter    
(of which I did not then treat), but only according to the order of 
thought (perception); so that my meaning was, that I clearly    
apprehended nothing, so far as I was conscious, as belonging to my  
essence, except that I was a thinking thing, or a thing possessing  
in itself the faculty of thinking. But I will show hereafter how, from  
the consciousness that nothing besides thinking belongs to the essence  
of the mind, it follows that nothing else does in truth belong to it.   
  The second objection is that it does not follow, from my  
possessing the idea of a thing more perfect than I am, that the idea    
itself is more perfect than myself, and much less that what is  
represented by the idea exists. 
  But I reply that in the term idea there is here something   
equivocal; for it may be taken either materially for an act of the  
understanding, and in this sense it cannot be said to be more   
perfect than I, or objectively, for the thing represented by that act,  
which, although it be not supposed to exist out of my understanding,    
may, nevertheless, be more perfect than myself, by reason of its    
essence. But, in the sequel of this treatise I will show more amply 
how, from my possessing the idea of a thing more perfect than   
myself, it follows that this thing really exists.   
  Besides these two objections, I have seen, indeed, two treatises  
of sufficient length relating to the present matter. In these,  
however, my conclusions, much more than my premises, were impugned, 
and that by arguments borrowed from the common-places of the atheists.  
But, as arguments of this sort can make no impression on the minds  
of those who shall rightly understand my reasonings, and as the 
judgments of many are so irrational and weak that they are persuaded    
rather by the opinions on a subject that are first presented to 
them, however false and opposed to reason they may be, than by a    
true and solid, but subsequently received, refutation of them, I am 
unwilling here to reply to these strictures from a dread of being,  
in the first instance, obliged to state them.   
  I will only say, in general, that all which the atheists commonly 
allege in favour of the non-existence of God arises continually from    
one or other of these two things, namely, either the ascription of  
human affections to deity, or the undue attribution to our minds of so  
much vigour and wisdom that we may essay to determine and comprehend    
both what God can and ought to do; hence all that is alleged by them    
will occasion us no difficulty, provided only we keep in remembrance    
that our minds must be considered finite, while Deity is    
incomprehensible and infinite.  
  Now that I have once, in some measure, made proof of the opinions of  
men regarding my work, I again undertake to treat of God and the human  
soul, and at the same time to discuss the principles of the entire  
first philosophy, without, however, expecting any commendation from 
the crowd for my endeavours, or a wide circle of readers. On the    
contrary, I would advise none to read this work, unless such as are 
able and willing to meditate with me in earnest, to detach their minds  
from commerce with the senses, and likewise to deliver themselves from  
all prejudice; and individuals of this character are, I well know,  
remarkably rare. But with regard to those who, without caring to    
comprehend the order and connection of the reasonings, shall study  
only detached clauses for the purpose of small but noisy criticism, as  
is the custom with many, I may say that such persons will not profit    
greatly by the reading of this treatise; and although perhaps they may  
find opportunity for cavilling in several places, they will yet hardly  
start any pressing objections, or such as shall be deserving of reply.  
  But since, indeed, I do not promise to satisfy others on all these    
subjects at first sight, nor arrogate so much to myself as to   
believe that I have been able to foresee all that may be the source of  
difficulty to each one, I shall expound, first of all, in the   
Meditations, those considerations by which I feel persuaded that I    
have arrived at a certain and evident knowledge of truth, in order  
that I may ascertain whether the reasonings which have prevailed    
with myself will also be effectual in convincing others. I will then    
reply to the objections of some men, illustrious for their genius   
and learning, to whom these meditations were sent for criticism before  
they were committed to the press; for these objections are so numerous  
and varied that I venture to anticipate that nothing, at least nothing  
of any moment, will readily occur to any mind which has not been    
touched upon in them.   
  Hence it is that I earnestly entreat my readers not to come to any    
judgment on the questions raised in the meditations until they have 
taken care to read the whole of the objections, with the relative   


  IN the First Meditation I expound the grounds on which we may 
doubt in general of all things, and especially of material objects, so  
long, at least, as we have no other foundations for the sciences    
than those we have hitherto possessed. Now, although the utility of 
a doubt so general may not be manifest at first sight, it is    
nevertheless of the greatest, since it delivers us from all prejudice,  
and affords the easiest pathway by which the mind may withdraw  
itself from the senses; and, finally, makes it impossible for us to 
doubt wherever we afterwards discover truth.    
  In the Second, the mind which, in the exercise of the freedom 
peculiar to itself, supposes that no object is, of the existence of 
which it has even the slightest doubt, finds that, meanwhile, it    
must itself exist. And this point is likewise of the highest moment,    
for the mind is thus enabled easily to distinguish what pertains to 
itself, that is, to the intellectual nature, from what is to be 
referred to the body. But since some, perhaps, will expect, at this 
stage of our progress, a statement of the reasons which establish   
the doctrine of the immortality of the soul, I think it proper here to  
make such aware, that it was my aim to write nothing of which I 
could not give exact demonstration, and that I therefore felt myself    
obliged to adopt an order similar to that in use among the  
geometers, viz., to premise all upon which the proposition in question  
depends, before coming to any conclusion respecting it. Now, the first  
and chief pre-requisite for the knowledge of the immortality of the 
soul is our being able to form the clearest possible conception 
(conceptus- concept) of the soul itself, and such as shall be 
absolutely distinct from all our notions of body; and how this is to    
be accomplished is there shown. There is required, besides this, the    
assurance that all objects which we clearly and distinctly think are    
true (really exist) in that very mode in which we think them: and this  
could not be established previously to the Fourth Meditation. Farther,  
it is necessary, for the same purpose, that we possess a distinct   
conception of corporeal nature, which is given partly in the Second 
and partly in the Fifth and Sixth Meditations. And, finally, on 
these grounds, we are necessitated to conclude, that all those objects  
which are clearly and distinctly conceived to be diverse substances,    
as mind and body, are substances really reciprocally distinct; and  
this inference is made in the Sixth Meditation. The absolute    
distinction of mind and body is, besides, confirmed in this Second  
Meditation, by showing that we cannot conceive body unless as   
divisible; while, on the other hand, mind cannot be conceived unless    
as indivisible. For we are not able to conceive the half of a mind, as  
we can of any body, however small, so that the natures of these two 
substances are to be held, not only as diverse, but even in some    
measure as contraries. I have not, however, pursued this discussion 
further in the present treatise, as well for the reason that these  
considerations are sufficient to show that the destruction of the mind  
does not follow from the corruption of the body, and thus to afford to  
men the hope of a future life, as also because the premises from which  
it is competent for us to infer the immortality of the soul, involve    
an explication of the whole principles of physics: in order to  
establish, in the first place, that generally all substances, that is,  
all things which can exist only in consequence of having been   
created by God, are in their own nature incorruptible, and can never    
cease to be, unless God himself, by refusing his concurrence to 
them, reduce them to nothing; and, in the second place, that body,  
taken generally, is a substance, and therefore can never perish, but    
that the human body, in as far as it differs from other bodies, is  
constituted only by a certain configuration of members, and by other    
accidents of this sort, while the human mind is not made up of  
accidents, but is a pure substance. For although all the accidents  
of the mind be changed- although, for example, it think certain 
things, will others, and perceive others, the mind itself does not  
vary with these changes; while, on the contrary, the human body is  
no longer the same if a change take place in the form of any of its 
parts: from which it follows that the body may, indeed, without 
difficulty perish, but that the mind is in its own nature immortal. 
  In the Third Meditation, I have unfolded at sufficient length, as 
appears to me, my chief argument for the existence of God. But yet, 
since I was there desirous to avoid the use of comparisons taken    
from material objects, that I might withdraw, as far as possible,   
the minds of my readers from the senses, numerous obscurities   
perhaps remain, which, however, will, I trust, be afterwards    
entirely removed in the replies to the objections: thus, among other    
things, it may be difficult to understand how the idea of a being   
absolutely perfect, which is found in our minds, possesses so much  
objective reality [i.e., participates by representation in so many    
degrees of being and perfection] that it must be held to arise from 
a course absolutely perfect. This is illustrated in the replies by the  
comparison of a highly perfect machine, the idea of which exists in 
the mind of some workmen; for as the objective (i.e., 
representative) perfection of this idea must have some cause, viz., 
either the science of the workman, or of some other person from whom    
he has received the idea, in the same way the idea of God, which is 
found in us, demands God himself for its cause. 
  In the Fourth, it is shown that all which we clearly and  
distinctly perceive (apprehend) is true; and, at the same time, is  
explained wherein consists the nature of error; points that require to  
be known as well for confirming the preceding truths, as for the    
better understanding of those that are to follow. But, meanwhile, it    
must be observed, that I do not at all there treat of Sin, that is, of  
error committed in the pursuit of good and evil, but of that sort   
alone which arises in the determination of the true and the false. Nor  
do I refer to matters of faith, or to the conduct of life, but only to  
what regards speculative truths, and such as are known by means of the  
natural light alone.    
  In the Fifth, besides the illustration of corporeal nature, taken 
generically, a new demonstration is given of the existence of God, not  
free, perhaps, any more than the former, from certain difficulties, 
but of these the solution will be found in the replies to the   
objections. I further show in what sense it is true that the certitude  
of geometrical demonstrations themselves is dependent on the knowledge  
of God. 
  Finally, in the Sixth, the act of the understanding   
(intellectio) is distinguished from that of the imagination   
(imaginatio); the marks of this distinction are described; the human  
mind is shown to be really distinct from the body, and, 
nevertheless, to be so closely conjoined therewith, as together to  
form, as it were, a unity. The whole of the errors which arise from 
the senses are brought under review, while the means of avoiding    
them are pointed out; and, finally, all the grounds are adduced from    
which the existence of material objects may be inferred; not, however,  
because I deemed them of great utility in establishing what they    
prove, viz., that there is in reality a world, that men are 
possessed of bodies, and the like, the truth of which no one of 
sound mind ever seriously doubted; but because, from a close    
consideration of them, it is perceived that they are neither so strong  
nor clear as the reasonings which conduct us to the knowledge of our    
mind and of God; so that the latter are, of all which come under human  
knowledge, the most certain and manifest- a conclusion which it was my  
single aim in these Meditations to establish; on which account I    
here omit mention of the various other questions which, in the  
course of the discussion, I had occasion likewise to consider.  

                             MEDITATION I   

  SEVERAL years have now elapsed since I first became aware that I had  
accepted, even from my youth, many false opinions for true, and that    
consequently what I afterwards based on such principles was highly  
doubtful; and from that time I was convinced of the necessity of    
undertaking once in my life to rid myself of all the opinions I had 
adopted, and of commencing anew the work of building from the   
foundation, if I desired to establish a firm and abiding    
superstructure in the sciences. But as this enterprise appeared to  
me to be one of great magnitude, I waited until I had attained an   
age so mature as to leave me no hope that at any stage of life more 
advanced I should be better able to execute my design. On this  
account, I have delayed so long that I should henceforth consider I 
was doing wrong were I still to consume in deliberation any of the  
time that now remains for action. To-day, then, since I have    
opportunely freed my mind from all cares [and am happily disturbed  
by no passions], and since I am in the secure possession of leisure in  
a peaceable retirement, I will at length apply myself earnestly and 
freely to the general overthrow of all my former opinions. But, to  
this end, it will not be necessary for me to show that the whole of 
these are false- a point, perhaps, which I shall never reach; but as    
even now my reason convinces me that I ought not the less carefully to  
withhold belief from what is not entirely certain and indubitable,  
than from what is manifestly false, it will be sufficient to justify    
the rejection of the whole if I shall find in each some ground for  
doubt. Nor for this purpose will it be necessary even to deal with  
each belief individually, which would be truly an endless labour; but,  
as the removal from below of the foundation necessarily involves the    
downfall of the whole edifice, I will at once approach the criticism    
of the principles on which all my former beliefs rested.    
  All that I have, up to this moment, accepted as possessed of the  
highest truth and certainty, I received either from or through the  
senses. I observed, however, that these sometimes misled us; and it is  
the part of prudence not to place absolute confidence in that by which  
we have even once been deceived.    
  But it may be said, perhaps, that, although the senses    
occasionally mislead us respecting minute objects, and such as are  
so far removed from us as to be beyond the reach of close observation,  
there are yet many other of their informations (presentations), of the  
truth of which it is manifestly impossible to doubt; as for example,    
that I am in this place, seated by the fire, clothed in a winter    
dressing-gown, that I hold in my hands this piece of paper, with other  
intimations of the same nature. But how could I deny that I possess 
these hands and this body, and withal escape being classed with 
persons in a state of insanity, whose brains are so disordered and  
clouded by dark bilious vapours as to cause them pertinaciously to  
assert that they are monarchs when they are in the greatest poverty;    
or clothed [in gold] and purple when destitute of any covering; or  
that their head is made of clay, their body of glass, or that they are  
gourds? I should certainly be not less insane than they, were I to  
regulate my procedure according to examples so extravagant. 
  Though this be true, I must nevertheless here consider that I am a    
man, and that, consequently, I am in the habit of sleeping, and 
representing to myself in dreams those same things, or even 
sometimes others less probable, which the insane think are presented    
to them in their waking moments. How often have I dreamt that I was in  
these familiar circumstances- that I was dressed, and occupied this 
place by the fire, when I was lying undressed in bed? At the present    
moment, however, I certainly look upon this paper with eyes wide    
awake; the head which I now move is not asleep; I extend this hand  
consciously and with express purpose, and I perceive it; the    
occurrences in sleep are not so distinct as all this. But I cannot  
forget that, at other times, I have been deceived in sleep by   
similar illusions; and, attentively considering those cases, I  
perceive so clearly that there exist no certain marks by which the  
state of waking can ever be distinguished from sleep, that I feel   
greatly astonished; and in amazement I almost persuade myself that I    
am now dreaming.    
  Let us suppose, then, that we are dreaming, and that all these    
particulars- namely, the opening of the eyes, the motion of the 
head, the forth-putting of the hands- are merely illusions; and even    
that we really possess neither an entire body nor hands such as we  
see. Nevertheless, it must be admitted at least that the objects which  
appear to us in sleep are, as it were, painted representations which    
could not have been formed unless in the likeness of realities; and,    
therefore, that those general objects, at all events- namely, eyes, 
a head, hands, and an entire body- are not simply imaginary, but    
really existent. For, in truth, painters themselves, even when they 
study to represent sirens and satyrs by forms the most fantastic and    
extraordinary, cannot bestow upon them natures absolutely new, but can  
only make a certain medley of the members of different animals; or  
if they chance to imagine something so novel that nothing at all    
similar has ever been seen before, and such as is, therefore, purely    
fictitious and absolutely false, it is at least certain that the    
colours of which this is composed are real. 
  And on the same principle, although these general objects, viz. [a    
body], eyes, a head, hands, and the like, be imaginary, we are  
nevertheless absolutely necessitated to admit the reality at least  
of some other objects still more simple and universal than these, of    
which, just as of certain real colours, all those images of things, 
whether true and real, or false and fantastic, that are found in our    
consciousness (cogitatio), are formed.    
  To this class of objects seem to belong corporeal nature in   
general and its extension; the figure of extended things, their 
quantity or magnitude, and their number, as also the place in, and the  
time during, which they exist, and other things of the same sort. We    
will not, therefore, perhaps reason illegitimately if we conclude from  
this that physics, astronomy, medicine, and all the other sciences  
that have for their end the consideration of composite objects, are 
indeed of a doubtful character; but that arithmetic, geometry, and the  
other sciences of the same class, which regard merely the simplest and  
most general objects, and scarcely inquire whether or not these are 
really existent, contain somewhat that is certain and indubitable: for  
whether I am awake or dreaming, it remains true that two and three  
make five, and that a square has but four sides; nor does it seem   
possible that truths so apparent can ever fall under a suspicion of 
falsity [or incertitude].   
  Nevertheless, the belief that there is a God who is all-powerful, 
and who created me, such as I am, has for a long time, obtained steady  
possession of my mind. How, then, do I know that he has not arranged    
that there should be neither earth, nor sky, nor any extended thing,    
nor figure, nor magnitude, nor place, providing at the same time,   
however, for [the rise in me of the perceptions of all these    
objects, and] the persuasion that these do not exist otherwise than as  
I perceive them? And further, as I sometimes think that others are  
in error respecting matters of which they believe themselves to 
possess a perfect knowledge, how do I know that I am not also deceived  
each time I add together two and three, or number the sides of a    
square, or form some judgment still more simple, if more simple indeed  
can be imagined? But perhaps Deity has not been willing that I  
should be thus deceived, for He is said to be supremely good. If,   
however, it were repugnant to the goodness of Deity to have created me  
subject to constant deception, it would seem likewise to be contrary    
to his goodness to allow me to be occasionally deceived; and yet it is  
clear that this is permitted. Some, indeed, might perhaps be found who  
would be disposed rather to deny the existence of a being so    
powerful than to believe that there is nothing certain. But let us for  
the present refrain from opposing this opinion, and grant that all  
which is here said of a Deity is fabulous: nevertheless, in whatever    
way it be supposed that I reached the state in which I exist,   
whether by fate, or chance, or by an endless series of antecedents and  
consequents, or by any other means, it is clear (since to be    
deceived and to err is a certain defect) that the probability of my 
being so imperfect as to be the constant victim of deception, will  
be increased exactly in proportion as the power possessed by the    
cause, to which they assign my origin, is lessened. To these    
reasonings I have assuredly nothing to reply, but am constrained at 
last to avow that there is nothing at all that I formerly believed  
to be true of which it is impossible to doubt, and that not through 
thoughtlessness or levity, but from cogent and maturely considered  
reasons; so that henceforward, if I desire to discover anything 
certain, I ought not the less carefully to refrain from assenting to    
those same opinions than to what might be shown to be manifestly    
  But it is not sufficient to have made these observations; care    
must be taken likewise to keep them in remembrance. For those old   
and customary opinions perpetually recur- long and familiar usage   
giving them the right of occupying my mind, even almost against my  
will, and subduing my belief; nor will I lose the habit of deferring    
to them and confiding in them so long as I shall consider them to be    
what in truth they are, viz., opinions to some extent doubtful, as I    
have already shown, but still highly probable, and such as it is    
much more reasonable to believe than deny. It is for this reason I  
am persuaded that I shall not be doing wrong, if, taking an opposite    
judgment of deliberate design, I become my own deceiver, by supposing,  
for a time, that all those opinions are entirely false and  
imaginary, until at length, having thus balanced my old by my new   
prejudices, my judgment shall no longer be turned aside by perverted    
usage from the path that may conduct to the perception of truth. For I  
am assured that, meanwhile, there will arise neither peril nor error    
from this course, and that I cannot for the present yield too much  
to distrust, since the end I now seek is not action but knowledge.  
  I will suppose, then, not that Deity, who is sovereignly good and 
the fountain of truth, but that some malignant demon, who is at once    
exceedingly potent and deceitful, has employed all his artifice to  
deceive me; I will suppose that the sky, the air, the earth,    
colours, figures, sounds, and all external things, are nothing  
better than the illusions of dreams, by means of which this being   
has laid snares for my credulity; I will consider myself as without 
hands, eyes, flesh, blood, or any of the senses, and as falsely 
believing that I am possessed of these; I will continue resolutely  
fixed in this belief, and if indeed by this means it be not in my   
power to arrive at the knowledge of truth, I shall at least do what is  
in my power, viz. [suspend my judgment], and guard with settled 
purpose against giving my assent to what is false, and being imposed    
upon by this deceiver, whatever be his power and artifice.  
  But this undertaking is arduous, and a certain indolence  
insensibly leads me back to my ordinary course of life; and just as 
the captive, who, perchance, was enjoying in his dreams an imaginary    
liberty, when he begins to suspect that it is but a vision, dreads  
awakening, and conspires with the agreeable illusions that the  
deception may be prolonged; so I, of my own accord, fall back into the  
train of my former beliefs, and fear to arouse myself from my slumber,  
lest the time of laborious wakefulness that would succeed this quiet    
rest, in place of bringing any light of day, should prove inadequate    
to dispel the darkness that will arise from the difficulties that have  
now been raised.    

                            MEDITATION II   
                   MORE EASILY KNOWN THAN THE BODY    

  THE Meditation of yesterday has filled my mind with so many   
doubts, that it is no longer in my power to forget them. Nor do I see,  
meanwhile, any principle on which they can be resolved; and, just as    
if I had fallen all of a sudden into very deep water, I am so   
greatly disconcerted as to be made unable either to plant my feet   
firmly on the bottom or sustain myself by swimming on the surface. I    
will, nevertheless, make an effort, and try anew the same path on   
which I had entered yesterday, that is, proceed by casting aside all    
that admits of the slightest doubt, not less than if I had  
discovered it to be absolutely false; and I will continue always in 
this track until I shall find something that is certain, or at  
least, if I can do nothing more, until I shall know with certainty  
that there is nothing certain. Archimedes, that he might transport the  
entire globe from the place it occupied to another, demanded only a 
point that was firm and immovable; so also, I shall be entitled to  
entertain the highest expectations, if I am fortunate enough to 
discover only one thing that is certain and indubitable.    
  I suppose, accordingly, that all the things which I see are false 
(fictitious); I believe that none of those objects which my fallacious  
memory represents ever existed; I suppose that I possess no senses; 
I believe that body, figure, extension, motion, and place are merely    
fictions of my mind. What is there, then, that can be esteemed true?    
Perhaps this only, that there is absolutely nothing certain.    
  But how do I know that there is not something different altogether    
from the objects I have now enumerated, of which it is impossible to    
entertain the slightest doubt? Is there not a God, or some being, by    
whatever name I may designate him, who causes these thoughts to 
arise in my mind? But why suppose such a being, for it may be I myself  
am capable of producing them? Am I, then, at least not something?   
But I before denied that I possessed senses or a body; I hesitate,  
however, for what follows from that? Am I so dependent on the body and  
the senses that without these I cannot exist? But I had the persuasion  
that there was absolutely nothing in the world, that there was no   
sky and no earth, neither minds nor bodies; was I not, therefore, at    
the same time, persuaded that I did not exist? Far from it; I   
assuredly existed, since I was persuaded. But there is I know not what  
being, who is possessed at once of the highest power and the deepest    
cunning, who is constantly employing all his ingenuity in deceiving 
me. Doubtless, then, I exist, since I am deceived; and, let him 
deceive me as he may, he can never bring it about that I am nothing,    
so long as I shall be conscious that I am something. So that it 
must, in fine, be maintained, all things being maturely and 
carefully considered, that this proposition (pronunciatum) I am, I    
exist, is necessarily true each time it is expressed by me, or  
conceived in my mind.   
  But I do not yet know with sufficient clearness what I am, though 
assured that I am; and hence, in the next place, I must take care,  
lest perchance I inconsiderately substitute some other object in    
room of what is properly myself, and thus wander from truth, even in    
that knowledge (cognition) which I hold to be of all others the most    
certain and evident. For this reason, I will now consider anew what 
I formerly believed myself to be, before I entered on the present   
train of thought; and of my previous opinion I will retrench all    
that can in the least be invalidated by the grounds of doubt I have 
adduced, in order that there may at length remain nothing but what  
is certain and indubitable. What then did I formerly think I was?   
Undoubtedly I judged that I was a man. But what is a man? Shall I   
say a rational animal? Assuredly not; for it would be necessary 
forthwith to inquire into what is meant by animal, and what by  
rational, and thus, from a single question, I should insensibly 
glide into others, and these more difficult than the first; nor do I    
now possess enough of leisure to warrant me in wasting my time amid 
subtleties of this sort. I prefer here to attend to the thoughts    
that sprung up of themselves in my mind, and were inspired by my own    
nature alone, when I applied myself to the consideration of what I  
was. In the first place, then, I thought that I possessed a 
countenance, hands, arms, and all the fabric of members that appears    
in a corpse, and which I called by the name of body. It further 
occurred to me that I was nourished, that I walked, perceived, and  
thought, and all those actions I referred to the soul; but what the 
soul itself was I either did not stay to consider, or, if I did, I  
imagined that it was something extremely rare and subtile, like 
wind, or flame, or ether, spread through my grosser parts. As regarded  
the body, I did not even doubt of its nature, but thought I distinctly  
knew it, and if I had wished to describe it according to the notions I  
then entertained, I should have explained myself in this manner: By 
body I understand all that can be terminated by a certain figure; that  
can be comprised in a certain place, and so fill a certain space as 
therefrom to exclude every other body; that can be perceived either by  
touch, sight, hearing, taste, or smell; that can be moved in different  
ways, not indeed of itself, but by something foreign to it by which it  
is touched [and from which it receives the impression]; for the 
power of self-motion, as likewise that of perceiving and thinking, I    
held as by no means pertaining to the nature of body; on the contrary,  
I was somewhat astonished to find such faculties existing in some   
  But [as to myself, what can I now say that I am], since I suppose 
there exists an extremely powerful, and, if I may so speak, 
malignant being, whose whole endeavours are directed towards deceiving  
me? Can I affirm that I possess any one of all those attributes of  
which I have lately spoken as belonging to the nature of body? After    
attentively considering them in my own mind, I find none of them    
that can properly be said to belong to myself. To recount them were 
idle and tedious. Let us pass, then, to the attributes of the soul. 
The first mentioned were the powers of nutrition and walking; but,  
if it be true that I have no body, it is true likewise that I am    
capable neither of walking nor of being nourished. Perception is    
another attribute of the soul; but perception too is impossible 
without the body: besides, I have frequently, during sleep, believed    
that I perceived objects which I afterwards observed I did not in   
reality perceive. Thinking is another attribute of the soul; and    
here I discover what properly belongs to myself. This alone is  
inseparable from me. I am- I exist: this is certain; but how often? As  
often as I think; for perhaps it would even happen, if I should wholly  
cease to think, that I should at the same time altogether cease to be.  
I now admit nothing that is not necessarily true: I am therefore,   
precisely speaking, only a thinking thing, that is, a mind (mens sive  
animus), understanding, or reason,- terms whose signification was  
before unknown to me. I am, however, a real thing, and really   
existent; but what thing? The answer was, a thinking thing. The 
question now arises, am I aught besides? I will stimulate my    
imagination with a view to discover whether I am not still something    
more than a thinking being. Now it is plain I am not the assemblage of  
members called the human body; I am not a thin and penetrating air  
diffused through all these members, or wind, or flame, or vapour, or    
breath, or any of all the things I can imagine; for I supposed that 
all these were not, and, without changing the supposition, I find that  
I still feel assured of my existence.   
  But it is true, perhaps, that those very things which I suppose to    
be non-existent, because they are unknown to me, are not in truth   
different from myself whom I know. This is a point I cannot determine,  
and do not now enter into any dispute regarding it. I can only judge    
of things that are known to me: I am conscious that I exist, and I who  
know that I exist inquire into what I am. It is, however, perfectly 
certain that the knowledge of my existence, thus precisely taken, is    
not dependent on things, the existence of which is as yet unknown to    
me: and consequently it is not dependent on any of the things I can 
feign in imagination. Moreover, the phrase itself, I frame an image 
(effingo), reminds me of my error; for I should in truth frame one    
if I were to imagine myself to be anything, since to imagine is 
nothing more than to contemplate the figure or image of a corporeal 
thing; but I already know that I exist, and that it is possible at the  
same time that all those images, and in general all that relates to 
the nature of body, are merely dreams [or chimeras]. From this I    
discover that it is not more reasonable to say, I will excite my    
imagination that I may know more distinctly what I am, than to express  
myself as follows: I am now awake, and perceive something real; but 
because my perception is not sufficiently clear, I will of express  
purpose go to sleep that my dreams may represent to me the object of    
my perception with more truth and clearness. And, therefore, I know 
that nothing of all that I can embrace in imagination belongs to the    
knowledge which I have of myself, and that there is need to recall  
with the utmost care the mind from this mode of thinking, that it   
may be able to know its own nature with perfect distinctness.   
  But what, then, am I? A thinking thing, it has been said. But what    
is a thinking thing? It is a thing that doubts, understands 
[conceives], affirms, denies, wills, refuses, that imagines also,   
and perceives. Assuredly it is not little, if all these properties  
belong to my nature. But why should they not belong to it? Am I not 
that very being who now doubts of almost everything; who, for all   
that, understands and conceives certain things, who affirms one 
alone as true, and denies the others; who desires to know more of   
them, and does not wish to be deceived; who imagines many things,   
sometimes even despite his will; and is likewise percipient of many,    
as if through the medium of the senses. Is there nothing of all this    
as true as that I am, even although I should be always dreaming, and    
although he who gave me being employed all his ingenuity to deceive 
me? Is there also any one of these attributes that can be properly  
distinguished from my thought, or that can be said to be separate from  
myself? For it is of itself so evident that it is I who doubt, I who    
understand, and I who desire, that it is here unnecessary to add    
anything by way of rendering it more clear. And I am as certainly   
the same being who imagines; for, although it may be (as I before   
supposed) that nothing I imagine is true, still the power of    
imagination does not cease really to exist in me and to form part of    
my thoughts. In fine, I am the same being who perceives, that is,   
who apprehends certain objects as by the organs of sense, since, in 
truth, I see light, hear a noise, and feel heat. But it will be said    
that these presentations are false, and that I am dreaming. Let it  
be so. At all events it is certain that I seem to see light, hear a 
noise, and feel heat; this cannot be false, and this is what in me  
is properly called perceiving (sentire), which is nothing else    
than thinking. From this I begin to know what I am with somewhat    
greater clearness and distinctness than heretofore. 
  But, nevertheless, it still seems to me, and I cannot help    
believing, that corporeal things, whose images are formed by thought    
[which fall under the senses], and are examined by the same, are known  
with much greater distinctness than that I know not what part of    
myself which is not imaginable; although, in truth, it may seem 
strange to say that I know and comprehend with greater distinctness 
things whose existence appears to me doubtful, that are unknown, and    
do not belong to me, than others of whose reality I am persuaded, that  
are known to me, and appertain to my proper nature; in a word, than 
myself. But I see clearly what is the state of the case. My mind is 
apt to wander, and will not yet submit to be restrained within the  
limits of truth. Let us therefore leave the mind to itself once 
more, and, according to it every kind of liberty [permit it to  
consider the objects that appear to it from without], in order that,    
having afterwards withdrawn it from these gently and opportunely    
[and fixed it on the consideration of its being and the properties  
it finds in itself], it may then be the more easily controlled. 
  Let us now accordingly consider the objects that are commonly 
thought to be [the most easily, and likewise] the most distinctly   
known, viz., the bodies we touch and see; not, indeed, bodies in    
general, for these general notions are usually somewhat more confused,  
but one body in particular. Take, for example, this piece of wax; it    
is quite fresh, having been but recently taken from the beehive; it 
has not yet lost the sweetness of the honey it contained; it still  
retains somewhat of the odour of the flowers from which it was  
gathered; its colour, figure, size, are apparent (to the sight); it is  
hard, cold, easily handled; and sounds when struck upon with the    
finger. In fine, all that contributes to make a body as distinctly  
known as possible, is found in the one before us. But, while I am   
speaking, let it be placed near the fire- what remained of the taste    
exhales, the smell evaporates, the colour changes, its figure is    
destroyed, its size increases, it becomes liquid, it grows hot, it can  
hardly be handled, and, although struck upon, it emits no sound.    
Does the same wax still remain after this change? It must be    
admitted that it does remain; no one doubts it, or judges otherwise.    
What, then, was it I knew with so much distinctness in the piece of 
wax? Assuredly, it could be nothing of all that I observed by means of  
the senses, since all the things that fell under taste, smell,  
sight, touch, and hearing are changed, and yet the same wax remains.    
It was perhaps what I now think, viz., that this wax was neither the    
sweetness of honey, the pleasant odour of flowers, the whiteness,   
the figure, nor the sound, but only a body that a little before 
appeared to me conspicuous under these forms, and which is now  
perceived under others. But, to speak precisely, what is it that I  
imagine when I think of it in this way? Let it be attentively   
considered, and, retrenching all that does not belong to the wax,   
let us see what remains. There certainly remains nothing, except    
something extended, flexible, and movable. But what is meant by 
flexible and movable? Is it not that I imagine that the piece of    
wax, being round, is capable of becoming square, or of passing from 
a square into a triangular figure? Assuredly such is not the case,  
because I conceive that it admits of an infinity of similar changes;    
and I am, moreover, unable to compass this infinity by imagination, 
and consequently this conception which I have of the wax is not the 
product of the faculty of imagination. But what now is this extension?  
Is it not also unknown? for it becomes greater when the wax is melted,  
greater when it is boiled, and greater still when the heat  
increases; and I should not conceive [clearly and] according to truth,  
the wax as it is, if I did not suppose that the piece we are    
considering admitted even of a wider variety of extension than I    
ever imagined. I must, therefore, admit that I cannot even  
comprehend by imagination what the piece of wax is, and that it is the  
mind alone (mens, Lat.; entendement, F.) which perceives it. I  
speak of one piece in particular; for, as to wax in general, this is    
still more evident. But what is the piece of wax that can be perceived  
only by the [understanding of] mind? It is certainly the same which 
I see, touch, imagine; and, in fine, it is the same which, from the 
beginning, I believed it to be. But (and this it is of moment to    
observe) the perception of it is neither an act of sight, of touch, 
nor of imagination, and never was either of these, though it might  
formerly seem so, but is simply an intuition (inspectio) of the   
mind, which may be imperfect and confused, as it formerly was, or very  
clear and distinct, as it is at present, according as the attention is  
more or less directed to the elements which it contains, and of 
which it is composed.   
  But, meanwhile, I feel greatly astonished when I observe [the 
weakness of my mind, and] its proneness to error. For although, 
without at all giving expression to what I think, I consider all    
this in my own mind, words yet occasionally impede my progress, and 
I am almost led into error by the terms of ordinary language. We    
say, for example, that we see the same wax when it is before us, and    
not that we judge it to be the same from its retaining the same colour  
and figure: whence I should forthwith be disposed to conclude that the  
wax is known by the act of sight, and not by the intuition of the mind  
alone, were it not for the analogous instance of human beings   
passing on in the street below, as observed from a window. In this  
case I do not fail to say that I see the men themselves, just as I say  
that I see the wax; and yet what do I see from the window beyond    
hats and cloaks that might cover artificial machines, whose motions 
might be determined by springs? But I judge that there are human    
beings from these appearances, and thus I comprehend, by the faculty    
of judgment alone which is in the mind, what I believed I saw with  
my eyes.    
  The man who makes it his aim to rise to knowledge superior to the 
common, ought to be ashamed to seek occasions of doubting from the  
vulgar forms of speech: instead, therefore, of doing this, I shall  
proceed with the matter in hand, and inquire whether I had a clearer    
and more perfect perception of the piece of wax when I first saw it,    
and when I thought I knew it by means of the external sense itself, 
or, at all events, by the common sense (sensus communis), as it is    
called, that is, by the imaginative faculty; or whether I rather    
apprehend it more clearly at present, after having examined with    
greater care, both what it is, and in what way it can be known. It  
would certainly be ridiculous to entertain any doubt on this point. 
For what, in that first perception, was there distinct? What did I  
perceive which any animal might not have perceived? But when I  
distinguish the wax from its exterior forms, and when, as if I had  
stripped it of its vestments, I consider it quite naked, it is  
certain, although some error may still be found in my judgment, that I  
cannot, nevertheless, thus apprehend it without possessing a human  
  But, finally, what shall I say of the mind itself, that is, of    
myself? for as yet I do not admit that I am anything but mind. What,    
then! I who seem to possess so distinct an apprehension of the piece    
of wax,- do I not know myself, both with greater truth and  
certitude, and also much more distinctly and clearly? For if I judge    
that the wax exists because I see it, it assuredly follows, much    
more evidently, that I myself am or exist, for the same reason: for it  
is possible that what I see may not in truth be wax, and that I do not  
even possess eyes with which to see anything; but it cannot be that 
when I see, or, which comes to the same thing, when I think I see, I    
myself who think am nothing. So likewise, if I judge that the wax   
exists because I touch it, it will still also follow that I am; and if  
I determine that my imagination, or any other cause, whatever it be,    
persuades me of the existence of the wax, I will still draw the same    
conclusion. And what is here remarked of the piece of wax is    
applicable to all the other things that are external to me. And 
further, if the [notion or] perception of wax appeared to me more   
precise and distinct, after that not only sight and touch, but many 
other causes besides, rendered it manifest to my apprehension, with 
how much greater distinctness must I now know myself, since all the 
reasons that contribute to the knowledge of the nature of wax, or of    
any body whatever, manifest still better the nature of my mind? And 
there are besides so many other things in the mind itself that  
contribute to the illustration of its nature, that those dependent  
on the body, to which I have here referred, scarcely merit to be taken  
into account.   
  But, in conclusion, I find I have insensibly reverted to the point I  
desired; for, since it is now manifest to me that bodies themselves 
are not properly perceived by the senses nor by the faculty of  
imagination, but by the intellect alone; and since they are not 
perceived because they are seen and touched, but only because they are  
understood [or rightly comprehended by thought], I readily discover 
that there is nothing more easily or clearly apprehended than my own    
mind. But because it is difficult to rid one's self so promptly of  
an opinion to which one has been long accustomed, it will be desirable  
to tarry for some time at this stage, that, by long continued   
meditation, I may more deeply impress upon my memory this new   

                            MEDITATION III  
                        OF GOD: THAT HE EXISTS    

  I WILL now close my eyes, I will stop my ears, I will turn away my    
senses from their objects, I will even efface from my consciousness 
all the images of corporeal things; or at least, because this can   
hardly be accomplished, I will consider them as empty and false; and    
thus, holding converse only with myself, and closely examining my   
nature, I will endeavour to obtain by degrees a more intimate and   
familiar knowledge of myself. I am a thinking (conscious) thing,    
that is, a being who doubts, affirms, denies, knows a few objects, and  
is ignorant of many,- [who loves, hates], wills, refuses,- who  
imagines likewise, and perceives; for, as I before remarked,    
although the things which I perceive or imagine are perhaps nothing at  
all apart from me [and in themselves], I am nevertheless assured    
that those modes of consciousness which I call perceptions and  
imaginations, in as far only as they are modes of consciousness, exist  
in me. And in the little I have said I think I have summed up all that  
I really know, or at least all that up to this time I was aware I   
knew. Now, as I am endeavouring to extend my knowledge more widely, 
I will use circumspection, and consider with care whether I can 
still discover in myself anything further which I have not yet  
hitherto observed. I am certain that I am a thinking thing; but do I    
not therefore likewise know what is required to render me certain of a  
truth? In this first knowledge, doubtless, there is nothing that gives  
me assurance of its truth except the clear and distinct perception  
of what I affirm, which would not indeed be sufficient to give me   
the assurance that what I say is true, if it could ever happen that 
anything I thus clearly and distinctly perceived should prove false;    
and accordingly it seems to me that I may now take as a general 
rule, that all that is very clearly and distinctly apprehended  
(conceived) is true.    
  Nevertheless I before received and admitted many things as wholly 
certain and manifest, which yet I afterwards found to be doubtful.  
What, then, were those? They were the earth, the sky, the stars, and    
all the other objects which I was in the habit of perceiving by the 
senses. But what was it that I clearly [and distinctly] perceived in    
them? Nothing more than that the ideas and the thoughts of those    
objects were presented to my mind. And even now I do not deny that  
these ideas are found in my mind. But there was yet another thing   
which I affirmed, and which, from having been accustomed to believe 
it, I thought I clearly perceived, although, in truth, I did not    
perceive it at all; I mean the existence of objects external to me, 
from which those ideas proceeded, and to which they had a perfect   
resemblance; and it was here I was mistaken, or if I judged correctly,  
this assuredly was not to be traced to any knowledge I possessed    
(the force of my perception, Lat.). 
  But when I considered any matter in arithmetic and geometry, that 
was very simple and easy, as, for example, that two and three added 
together make five, and things of this sort, did I not view them    
with at least sufficient clearness to warrant me in affirming their 
truth? Indeed, if I afterwards judged that we ought to doubt of 
these things, it was for no other reason than because it occurred to    
me that a God might perhaps have given me such a nature as that I   
should be deceived, even respecting the matters that appeared to me 
the most evidently true. But as often as this preconceived opinion  
of the sovereign power of a God presents itself to my mind, I am    
constrained to admit that it is easy for him, if he wishes it, to   
cause me to err, even in matters where I think I possess the highest    
evidence; and, on the other hand, as often as I direct my attention to  
things which I think I apprehend with great clearness I am so   
persuaded of their truth that I naturally break out into expressions    
such as these: Deceive me who may, no one will yet ever be able to  
bring it about that I am not, so long as I shall be conscious that I    
am, or at any future time cause it to be true that I have never 
been, it being now true that I am, or make two and three more or    
less than five, in supposing which, and other like absurdities, I   
discover a manifest contradiction.  
  And in truth, as I have no ground for believing that Deity is 
deceitful, and as, indeed, I have not even considered the reasons by    
which the existence of a Deity of any kind is established, the  
ground of doubt that rests only on this supposition is very slight, 
and, so to speak, metaphysical. But, that I may be able wholly to   
remove it, I must inquire whether there is a God, as soon as an 
opportunity of doing so shall present itself; and if I find that there  
is a God, I must examine likewise whether he can be a deceiver; for,    
without the knowledge of these two truths, I do not see that I can  
ever be certain of anything. And that I may be enabled to examine this  
without interrupting the order of meditation I have proposed to myself  
[which is, to pass by degrees from the notions that I shall find first  
in my mind to those I shall afterwards discover in it], it is   
necessary at this stage to divide all my thoughts into certain  
classes, and to consider in which of these classes truth and error  
are, strictly speaking, to be found.    
  Of my thoughts some are, as it were, images of things, and to 
these alone properly belongs the name idea; as when I think   
[represent to my mind] a man, a chimera, the sky, an angel, or God. 
Others, again, have certain other forms; as when I will, fear, affirm,  
or deny, I always, indeed, apprehend something as the object of my  
thought, but I also embrace in thought something more than the  
representation of the object; and of this class of thoughts some are    
called volitions or affections, and others judgments.   
  Now, with respect to ideas, if these are considered only in   
themselves, and are not referred to any object beyond them, they    
cannot, properly speaking, be false; for whether I imagine a goat or a  
chimera, it is not less true that I imagine the one than the other. 
Nor need we fear that falsity may exist in the will or affections;  
for, although I may desire objects that are wrong, and even that never  
existed, it is still true that I desire them. There thus only remain    
our judgments, in which we must take diligent heed that we be not   
deceived. But the chief and most ordinary error that arises in them 
consists in judging that the ideas which are in us are like or  
conformed to the things that are external to us; for assuredly, if  
we but considered the ideas themselves as certain modes of our thought  
(consciousness), without referring them to anything beyond, they would  
hardly afford any occasion of error.    
  But, among these ideas, some appear to me to be innate, others    
adventitious, and others to be made by myself (factitious); for, as 
I have the power of conceiving what is called a thing, or a truth,  
or a thought, it seems to me that I hold this power from no other   
source than my own nature; but if I now hear a noise, if I see the  
sun, or if I feel heat, I have all along judged that these  
sensations proceeded from certain objects existing out of myself; and,  
in fine, it appears to me that sirens, hippogryphs, and the like,   
are inventions of my own mind. But I may even perhaps come to be of 
opinion that all my ideas are of the class which I call 
adventitious, or that they are all innate, or that they are all 
factitious, for I have not yet clearly discovered their true origin;    
and what I have here principally to do is to consider, with 
reference to those that appear to come from certain objects without 
me, what grounds there are for thinking them like these objects.    
  The first of these grounds is that it seems to me I am so taught  
by nature; and the second that I am conscious that those ideas are not  
dependent on my will, and therefore not on myself, for they are 
frequently presented to me against my will,- as at present, whether 
I will or not, I feel heat; and I am thus persuaded that this   
sensation or idea (sensum vel ideam) of heat is produced in me by 
something different from myself, viz., by the heat of the fire by   
which I sit. And it is very reasonable to suppose that this object  
impresses me with its own likeness rather than any other thing. 
  But I must consider whether these reasons are sufficiently strong 
and convincing. When I speak of being taught by nature in this matter,  
I understand by the word nature only a certain spontaneous impetus  
that impels me to believe in a resemblance between ideas and their  
objects, and not a natural light that affords a knowledge of its    
truth. But these two things are widely different; for what the natural  
light shows to be true can be in no degree doubtful, as, for    
example, that I am because I doubt, and other truths of the like kind:  
inasmuch as I possess no other faculty whereby to distinguish truth 
from error, which can teach me the falsity of what the natural light    
declares to be true, and which is equally trustworthy; but with 
respect to [seemingly] natural impulses, I have observed, when the  
question related to the choice of right or wrong in action, that    
they frequently led me to take the worse part; nor do I see that I  
have any better ground for following them in what relates to truth and  
error. Then, with respect to the other reason, which is that because    
these ideas do not depend on my will, they must arise from objects  
existing without me, I do not find it more convincing than the former;  
for, just as those natural impulses, of which I have lately spoken, 
are found in me, notwithstanding that they are not always in harmony    
with my will, so likewise it may be that I possess some power not   
sufficiently known to myself capable of producing ideas without the 
aid of external objects, and, indeed, it has always hitherto    
appeared to me that they are formed during sleep, by some power of  
this nature, without the aid of aught external. And, in fine, although  
I should grant that they proceeded from those objects, it is not a  
necessary consequence that they must be like them. On the contrary, 
I have observed, in a number of instances, that there was a great   
difference between the object and its idea. Thus, for example, I    
find in my mind two wholly diverse ideas of the sun; the one, by which  
it appears to me extremely small, draws its origin from the senses, 
and should be placed in the class of adventitious ideas; the other, by  
which it seems to be many times larger than the whole earth, is 
taken up on astronomical grounds, that is, elicited from certain    
notions born with me, or is framed by myself in some other manner.  
These two ideas cannot certainly both resemble the same sun; and    
reason teaches me that the one which seems to have immediately  
emanated from it is the most unlike. And these things sufficiently  
prove that hitherto it has not been from a certain and deliberate   
judgment, but only from a sort of blind impulse, that I believed in 
the existence of certain things different from myself, which, by the    
organs of sense, or by whatever other means it might be, conveyed   
their ideas or images into my mind [and impressed it with their 
  But there is still another way of inquiring whether, of the   
objects whose ideas are in my mind, there are any that exist out of 
me. If ideas are taken in so far only as they are certain modes of  
consciousness, I do not remark any difference or inequality among   
them, and all seem, in the same manner, to proceed from myself; but,    
considering them as images, of which one represents one thing and   
another a different, it is evident that a great diversity obtains   
among them. For, without doubt, those that represent substances are 
something more, and contain in themselves, so to speak, more objective  
reality [that is, participate by representation in higher degrees of    
being or perfection] than those that represent only modes or    
accidents; and again, the idea by which I conceive a God    
[sovereign], eternal, infinite [immutable], all-knowing, all-powerful,  
and the creator of all things that are out of himself,- this, I say,    
has certainly in it more objective reality than those ideas by which    
finite substances are represented.  
  Now, it is manifest by the natural light that there must at least be  
as much reality in the efficient and total cause as in its effect; for  
whence can the effect draw its reality if not from its cause? and   
how could the cause communicate to it this reality unless it possessed  
it in itself? And hence it follows, not only that what is cannot be 
produced by what is not, but likewise that the more perfect,- in other  
words, that which contains in itself more reality,- cannot be the   
effect of the less perfect: and this is not only evidently true of  
those effects, whose reality is actual or formal, but likewise of   
ideas, whose reality is only considered as objective. Thus, for 
example, the stone that is not yet in existence, not only cannot now    
commence to be, unless it be produced by that which possesses in    
itself, formally or eminently, all that enters into its composition 
[in other words, by that which contains in itself the same  
properties that are in the stone, or others superior to them]; and  
heat can only be produced in a subject that was before devoid of it,    
by a cause that is of an order [degree or kind] at least as perfect as  
heat; and so of the others. But further, even the idea of the heat, or  
of the stone, cannot exist in me unless it be put there by a cause  
that contains, at least, as much reality as I conceive existent in the  
heat or in the stone: for, although that cause may not transmit into    
my idea anything of its actual or formal reality, we ought not on this  
account to imagine that it is less real; but we ought to consider that  
[as every idea is a work of the mind], its nature is such as of itself  
to demand no other formal reality than that which it borrows from   
our consciousness, of which it is but a mode [that is, a manner or way  
of thinking]. But in order that an idea may contain this objective  
reality rather than that, it must doubtless derive it from some 
cause in which is found at least as much formal reality as the idea 
contains an objective; for, if we suppose that there is found in an 
idea anything which was not in its cause, it must of course derive  
this from nothing. But, however imperfect may be the mode of existence  
by which a thing is objectively [or by representation] in the   
understanding by its idea, we certainly cannot, for all that, allege    
that this mode of existence is nothing, nor, consequently, that the 
idea owes its origin to nothing. Nor must it be imagined that, since    
the reality which is considered in these ideas is only objective,   
the same reality need not be formally (actually) in the causes of   
these ideas, but only objectively; for, just as the mode of existing    
objectively belongs to ideas by their peculiar nature, so likewise the  
mode of existing formally appertains to the causes of these ideas   
(at least to the first and principal), by their peculiar nature. And    
although an idea may give rise to another idea, this regress cannot,    
nevertheless, be infinite; we must in the end reach a first idea,   
the cause of which is, as it were, the archetype in which all the   
reality [or perfection] that is found objectively [or by    
representation] in these ideas is contained formally [and in act]. I    
am thus clearly taught by the natural light that ideas exist in me  
as pictures or images, which may in truth readily fall short of the 
perfection of the objects from which they are taken, but can never  
contain anything greater or more perfect.   
  And in proportion to the time and care with which I examine all   
those matters, the conviction of their truth brightens and becomes  
distinct. But, to sum up, what conclusion shall I draw from it all? It  
is this;- if the objective reality [or perfection] of any one of my 
ideas be such as clearly to convince me, that this same reality exists  
in me neither formally nor eminently, and if, as follows from this, 
I myself cannot be the cause of it, it is a necessary consequence that  
I am not alone in the world, but that there is besides myself some  
other being who exists as the cause of that idea; while, on the 
contrary, if no such idea be found in my mind, I shall have no  
sufficient ground of assurance of the existence of any other being  
besides myself, for, after a most careful search, I have, up to this    
moment, been unable to discover any other ground.   
  But, among these my ideas, besides that which represents myself,  
respecting which there can be here no difficulty, there is one that 
represents a God; others that represent corporeal and inanimate 
things; others angels; others animals; and, finally, there are some 
that represent men like myself. But with respect to the ideas that  
represent other men, or animals, or angels, I can easily suppose    
that they were formed by the mingling and composition of the other  
ideas which I have of myself, of corporeal things, and of God,  
although there were, apart from myself, neither men, animals, nor   
angels. And with regard to the ideas of corporeal objects, I never  
discovered in them anything so great or excellent which I myself did    
not appear capable of originating; for, by considering these ideas  
closely and scrutinising them individually, in the same way that I  
yesterday examined the idea of wax, I find that there is but little in  
them that is clearly and distinctly perceived. As belonging to the  
class of things that are clearly apprehended, I recognise the   
following, viz., magnitude or extension in length, breadth, and depth;  
figure, which results from the termination of extension; situation, 
which bodies of diverse figures preserve with reference to each other;  
and motion or the change of situation; to which may be added    
substance, duration, and number. But with regard to light, colours, 
sounds, odours, tastes, heat, cold and the other tactile qualities, 
they are thought with so much obscurity and confusion, that I cannot    
determine even whether they are true or false; in other words, whether  
or not the ideas I have of these qualities are in truth the ideas of    
real objects. For although I before remarked that it is only in 
judgments that formal falsity, or falsity properly so called, can be    
met with, there may nevertheless be found in ideas a certain    
material falsity, which arises when they represent what is nothing  
as if it were something. Thus, for example, the ideas I have of cold    
and heat are so far from being clear and distinct, that I am unable 
from them to discover whether cold is only the privation of heat, or    
heat the privation of cold; or whether they are or are not real 
qualities: and since, ideas being as it were images, there can be none  
that does not seem to us to represent some object, the idea which   
represents cold as something real and positive will not improperly  
be called false, if it be correct to say that cold is nothing but a 
privation of heat; and so in other cases. To ideas of this kind,    
indeed, it is not necessary that I should assign any author besides 
myself: for if they are false, that is, represent objects that are  
unreal, the natural light teaches me that they proceed from nothing;    
in other words, that they are in me only because something is   
wanting to the perfection of my nature; but if these ideas are true,    
yet because they exhibit to me so little reality that I cannot even 
distinguish the object represented from non-being, I do not see why 
I should not be the author of them. 
  With reference to those ideas of corporeal things that are clear and  
distinct, there are some which, as appears to me, might have been   
taken from the idea I have of myself, as those of substance, duration,  
number, and the like. For when I think that a stone is a substance, or  
a thing capable of existing of itself, and that I am likewise a 
substance, although I conceive that I am a thinking and non-extended    
thing, and that the stone, on the contrary, is extended and 
unconscious, there being thus the greatest diversity between the two    
concepts,- yet these two ideas seem to have this in common that they    
both represent substances. In the same way, when I think of myself  
as now existing, and recollect besides that I existed some time ago,    
and when I am conscious of various thoughts whose number I know, I  
then acquire the ideas of duration and number, which I can  
afterwards transfer to as many objects as I please. With respect to 
the other qualities that go to make up the ideas of corporeal objects,  
viz., extension, figure, situation, and motion, it is true that they    
are not formally in me, since I am merely a thinking being; but 
because they are only certain modes of substance, and because I myself  
am a substance, it seems possible that they may be contained in me  
  There only remains, therefore, the idea of God, in which I must   
consider whether there is anything that cannot be supposed to   
originate with myself. By the name God, I understand a substance    
infinite [eternal, immutable], independent, all-knowing, all-powerful,  
and by which I myself, and every other thing that exists, if any    
such there be, were created. But these properties are so great and  
excellent, that the more attentively I consider them the less I feel    
persuaded that the idea I have of them owes its origin to myself    
alone. And thus it is absolutely necessary to conclude, from all    
that I have before said, that God exists: for though the idea of    
substance be in my mind owing to this, that I myself am a substance, I  
should not, however, have the idea of an infinite substance, seeing 
I am a finite being, unless it were given me by some substance in   
reality infinite.   
  And I must not imagine that I do not apprehend the infinite by a  
true idea, but only by the negation of the finite, in the same way  
that I comprehend repose and darkness by the negation of motion and 
light: since, on the contrary, I clearly perceive that there is more    
reality in the infinite substance than in the finite, and therefore 
that in some way I possess the perception (notion) of the infinite  
before that of the finite, that is, the perception of God before    
that of myself, for how could I know that I doubt, desire, or that  
something is wanting to me, and that I am not wholly perfect, if I  
possessed no idea of a being more perfect than myself, by comparison    
of which I knew the deficiencies of my nature?  
  And it cannot be said that this idea of God is perhaps materially 
false, and consequently that it may have arisen from nothing [in other  
words, that it may exist in me from my imperfection], as I before said  
of the ideas of heat and cold, and the like: for, on the contrary,  
as this idea is very clear and distinct, and contains in itself more    
objective reality than any other, there can be no one of itself more    
true, or less open to the suspicion of falsity. 
  The idea, I say, of a being supremely perfect, and infinite, is in    
the highest degree true; for although, perhaps, we may imagine that 
such a being does not exist, we cannot, nevertheless, suppose that his  
idea represents nothing real, as I have already said of the idea of 
cold. It is likewise clear and distinct in the highest degree, since    
whatever the mind clearly and distinctly conceives as real or true, 
and as implying any perfection, is contained entire in this idea.   
And this is true, nevertheless, although I do not comprehend the    
infinite, and although there may be in God an infinity of things    
that I cannot comprehend, nor perhaps even compass by thought in any    
way; for it is of the nature of the infinite that it should not be  
comprehended by the finite; and it is enough that I rightly understand  
this, and judge that all which I clearly perceive, and in which I know  
there is some perfection, and perhaps also an infinity of properties    
of which I am ignorant, are formally or eminently in God, in order  
that the idea I have of him may become the most true, clear, and    
distinct of all the ideas in my mind.   
  But perhaps I am something more than I suppose myself to be, and  
it may be that all those perfections which I attribute to God, in some  
way exist potentially in me, although they do not yet show themselves,  
and are not reduced to act. Indeed, I am already conscious that my  
knowledge is being increased [and perfected] by degrees; and I see  
nothing to prevent it from thus gradually increasing to infinity,   
nor any reason why, after such increase and perfection, I should not    
be able thereby to acquire all the other perfections of the Divine  
nature; nor, in fine, why the power I possess of acquiring those    
perfections, if it really now exist in me, should not be sufficient to  
produce the ideas of them. Yet, on looking more closely into the    
matter, I discover that this cannot be; for, in the first place,    
although it were true that my knowledge daily acquired new degrees  
of perfection, and although there were potentially in my nature much    
that was not as yet actually in it, still all these excellences make    
not the slightest approach to the idea I have of the Deity, in whom 
there is no perfection merely potentially [but all actually] existent;  
for it is even an unmistakable token of imperfection in my  
knowledge, that it is augmented by degrees. Further, although my    
knowledge increase more and more, nevertheless I am not, therefore, 
induced to think that it will ever be actually infinite, since it   
can never reach that point beyond which it shall be incapable of    
further increase. But I conceive God as actually infinite, so that  
nothing can be added to his perfection. And, in fine, I readily 
perceive that the objective being of an idea cannot be produced by a    
being that is merely potentially existent, which, properly speaking,    
is nothing, but only by a being existing formally or actually.  
  And, truly, I see nothing in all that I have now said which it is 
not easy for any one, who shall carefully consider it, to discern by    
the natural light; but when I allow my attention in some degree to  
relax, the vision of my mind being obscured, and, as it were,   
blinded by the images of sensible objects, I do not readily remember    
the reason why the idea of a being more perfect than myself, must of    
necessity have proceeded from a being in reality more perfect. On this  
account I am here desirous to inquire further, whether I, who   
possess this idea of God, could exist supposing there were no God. And  
I ask, from whom could I, in that case, derive my existence? Perhaps    
from myself, or from my parents, or from some other causes less 
perfect than God; for anything more perfect, or even equal to God,  
cannot be thought or imagined. But if I [were independent of every  
other existence, and] were myself the author of my being, I should  
doubt of nothing, I should desire nothing, and, in fine, no perfection  
would be awanting to me; for I should have bestowed upon myself 
every perfection of which I possess the idea, and I should thus be  
God. And it must not be imagined that what is now wanting to me is  
perhaps of more difficult acquisition than that of which I am   
already possessed; for, on the contrary, it is quite manifest that  
it was a matter of much higher difficulty that I, a thinking being, 
should arise from nothing, than it would be for me to acquire the   
knowledge of many things of which I am ignorant, and which are  
merely the accidents of a thinking substance; and certainly, if I   
possessed of myself the greater perfection of which I have now  
spoken [in other words, if I were the author of my own existence], I    
would not at least have denied to myself things that may be more    
easily obtained [as that infinite variety of knowledge of which I am    
at present destitute]. I could not, indeed, have denied to myself   
any property which I perceive is contained in the idea of God, because  
there is none of these that seems to me to be more difficult to make    
or acquire; and if there were any that should happen to be more 
difficult to acquire, they would certainly appear so to me  
(supposing that I myself were the source of the other things I  
possess), because I should discover in them a limit to my power. And    
though I were to suppose that I always was as I now am, I should    
not, on this ground, escape the force of these reasonings, since it 
would not follow, even on this supposition, that no author of my    
existence needed to be sought after. For the whole time of my life may  
be divided into an infinity of parts, each of which is in no way    
dependent on any other; and, accordingly, because I was in existence a  
short time ago, it does not follow that I must now exist, unless in 
this moment some cause create me anew, as it were,- that is,    
conserve me. In truth, it is perfectly clear and evident to all who 
will attentively consider the nature of duration that the conservation  
of a substance, in each moment of its duration, requires the same   
power and act that would be necessary to create it, supposing it    
were not yet in existence; so that it is manifestly a dictate of the    
natural light that conservation and creation differ merely in   
respect of our mode of thinking [and not in reality]. All that is here  
required, therefore, is that I interrogate myself to discover   
whether I possess any power by means of which I can bring it about  
that I, who now am, shall exist a moment afterwards: for, since I am    
merely a thinking thing (or since, at least, the precise question,  
in the meantime, is only of that part of myself), if such a power   
resided in me, I should, without doubt, be conscious of it; but I am    
conscious of no such power, and thereby I manifestly know that I am 
dependent upon some being different from myself.    
  But perhaps the being upon whom I am dependent is not God, and I  
have been produced either by my parents, or by some causes less 
perfect than Deity. This cannot be: for, as I before said, it is    
perfectly evident that there must at least be as much reality in the    
cause as in its effect; and accordingly, since I am a thinking thing    
and possess in myself an idea of God, whatever in the end be the cause  
of my existence, it must of necessity be admitted that it is    
likewise a thinking being, and that it possesses in itself the idea 
and all the perfections I attribute to Deity. Then it may again be  
inquired whether this cause owes its origin and existence to itself,    
or to some other cause. For if it be self-existent, it follows, from    
what I have before laid down, that this cause is God; for, since it 
possesses the perfection of self-existence, it must likewise,   
without doubt, have the power of actually possessing every  
perfection of which it has the idea,- in other words, all the   
perfections I conceive to belong to God. But if it owe its existence    
to another cause than itself, we demand again, for a similar reason,    
whether this second cause exists of itself or through some other,   
until, from stage to stage, we at length arrive at an ultimate  
cause, which will be God. And it is quite manifest that in this matter  
there can be no infinite regress of causes, seeing that the question    
raised respects not so much the cause which once produced me, as    
that by which I am at this present moment conserved.    
  Nor can it be supposed that several causes concerned in my    
production, and that from one I received the idea of one of the 
perfections I attribute to Deity, and from another the idea of some 
other, and thus that all those perfections are indeed found 
somewhere in the universe, but do not all exist together in a single    
being who is God; for, on the contrary, the unity, the simplicity or    
inseparability of all the properties of Deity, is one of the chief  
perfections I conceive him to possess; and the idea of this unity of    
all the perfections of Deity could certainly not be put into my mind    
by any cause from which I did not likewise receive the ideas of all 
the other perfections; for no power could enable me to embrace them in  
an inseparable unity, without at the same time giving me the knowledge  
of what they were [and of their existence in a particular mode].    
  Finally, with regard to my parents [from whom it appears I    
sprung], although all that I believed respecting them be true, it does  
not, nevertheless, follow that I am conserved by them, or even that 
I was produced by them, in so far as I am a thinking being. All 
that, at the most, they contributed to my origin was the giving of  
certain dispositions (modifications) to the matter in which I have  
hitherto judged that I or my mind, which is what alone I now    
consider to be myself, is enclosed; and thus there can here be no   
difficulty with respect to them, and it is absolutely necessary to  
conclude from this alone that I am, and possess the idea of a being 
absolutely perfect, that is, of God, that his existence is most 
clearly demonstrated.   
  There remains only the inquiry as to the way in which I received  
this idea from God; for I have not drawn it from the senses, nor is it  
even presented to me unexpectedly, as is usual with the ideas of    
sensible objects, when these are presented or appear to be presented    
to the external organs of the senses; it is not even a pure production  
or fiction of my mind, for it is not in my power to take from or add    
to it; and consequently there but remains the alternative that it is    
innate, in the same way as is the idea of myself. And, in truth, it is  
not to be wondered at that God, at my creation, implanted this idea in  
me, that it might serve, as it were, for the mark of the workman    
impressed on his work; and it is not also necessary that the mark   
should be something different from the work itself; but considering 
only that God is my creator, it is highly probable that he in some way  
fashioned me after his own image and likeness, and that I perceive  
this likeness, in which is contained the idea of God, by the same   
faculty by which I apprehend myself,- in other words, when I make   
myself the object of reflection, I not only find that I am an   
incomplete [imperfect] and dependent being, and one who unceasingly 
aspires after something better and greater than he is; but, at the  
same time, I am assured likewise that he upon whom I am dependent   
possesses in himself all the goods after which I aspire [and the ideas  
of which I find in my mind], and that not merely indefinitely and   
potentially, but infinitely and actually, and that he is thus God. And  
the whole force of the argument of which I have here availed myself to  
establish the existence of God, consists in this, that I perceive I 
could not possibly be of such a nature as I am, and yet have in my  
mind the idea of a God, if God did not in reality exist,- this same 
God, I say, whose idea is in my mind- that is, a being who possesses    
all those lofty perfections, of which the mind may have some slight 
conception, without, however, being able fully to comprehend them,- 
and who is wholly superior to all defect [and has nothing that marks    
imperfection]: whence it is sufficiently manifest that he cannot be 
a deceiver, since it is a dictate of the natural light that all 
fraud and deception spring from some defect.    
  But before I examine this with more attention, and pass on to the 
consideration of other truths that may be evolved out of it, I think    
it proper to remain here for some time in the contemplation of God  
himself- that I may ponder at leisure his marvellous attributes- and    
behold, admire, and adore the beauty of this light so unspeakably   
great, as far, at least, as the strength of my mind, which is to    
some degree dazzled by the sight, will permit. For just as we learn by  
faith that the supreme felicity of another life consists in the 
contemplation of the Divine majesty alone, so even now we learn from    
experience that a like meditation, though incomparably less perfect,    
is the source of the highest satisfaction of which we are   
susceptible in this life.   

                            MEDITATION IV   
                          OF TRUTH AND ERROR  

  I HAVE been habituated these bygone days to detach my mind from   
the senses, and I have accurately observed that there is exceedingly    
little which is known with certainty respecting corporeal objects,- 
that we know much more of the human mind, and still more of God 
himself. I am thus able now without difficulty to abstract my mind  
from the contemplation of [sensible or] imaginable objects, and 
apply it to those which, as disengaged from all matter, are purely  
intelligible. And certainly the idea I have of the human mind in so 
far as it is a thinking thing, and not extended in length, breadth, 
and depth, and participating in none of the properties of body, is  
incomparably more distinct than the idea of any corporeal object;   
and when I consider that I doubt, in other words, that I am an  
incomplete and dependent being, the idea of a complete and independent  
being, that is to say of God, occurs to my mind with so much clearness  
and distinctness,- and from the fact alone that this idea is found  
in me, or that I who possess it exist, the conclusions that God 
exists, and that my own existence, each moment of its continuance,  
is absolutely dependent upon him, are so manifest,- as to lead me to    
believe it impossible that the human mind can know anything with    
more clearness and certitude. And now I seem to discover a path that    
will conduct us from the contemplation of the true God, in whom are 
contained all the treasures of science and wisdom, to the knowledge of  
the other things in the universe.   
  For, in the first place, I discover that it is impossible for him 
ever to deceive me, for in all fraud and deceit there is a certain  
imperfection: and although it may seem that the ability to deceive  
is a mark of subtlety or power, yet the will testifies without doubt    
of malice and weakness; and such, accordingly, can be found in God. In  
the next place, I am conscious that I possess a certain faculty of  
judging [or discerning truth from error], which I doubtless received    
from God, along with whatever else is mine; and since it is impossible  
that he should will to deceive me, it is likewise certain that he   
has not given me a faculty that will ever lead me into error, provided  
I use it aright.    
  And there would remain no doubt on this head, did it not seem to  
follow from this, that I can never therefore be deceived; for if all I  
possess be from God, and if he planted in me no faculty that is 
deceitful, it seems to follow that I can never fall into error. 
Accordingly, it is true that when I think only of God (when I look  
upon myself as coming from God, Fr.), and turn wholly to him, I 
discover [in myself] no cause of error or falsity: but immediately  
thereafter, recurring to myself, experience assures me that I am    
nevertheless subject to innumerable errors. When I come to inquire  
into the cause of these, I observe that there is not only present to    
my consciousness a real and positive idea of God, or of a being 
supremely perfect, but also, so to speak, a certain negative idea of    
nothing,- in other words, of that which is at an infinite distance  
from every sort of perfection, and that I am, as it were, a mean    
between God and nothing, or placed in such a way between absolute   
existence and non-existence, that there is in truth nothing in me to    
lead me into error, in so far as an absolute being is my creator;   
but that, on the other hand, as I thus likewise participate in some 
degree of nothing or of non-being, in other words, as I am not  
myself the supreme Being, and as I am wanting in many perfections,  
it is not surprising I should fall into error. And I hence discern  
that error, so far as error is not something real, which depends for    
its existence on God, but is simply defect; and therefore that, in  
order to fall into it, it is not necessary God should have given me 
a faculty expressly for this end, but that my being deceived arises 
from the circumstance that the power which God has given me of  
discerning truth from error is not infinite.    
  Nevertheless this is not yet quite satisfactory; for error is not 
a pure negation [in other words, it is not the simple deficiency or 
want of some knowledge which is not due], but the privation or want of  
some knowledge which it would seem I ought to possess. But, on  
considering the nature of God, it seems impossible that he should have  
planted in his creature any faculty not perfect in its kind, that   
is, wanting in some perfection due to it: for if it be true, that in    
proportion to the skill of the maker the perfection of his work is  
greater, what thing can have been produced by the supreme Creator of    
the universe that is not absolutely perfect in all its parts? And   
assuredly there is no doubt that God could have created me such as  
that I should never be deceived; it is certain, likewise, that he   
always wills what is best: is it better, then, that I should be 
capable of being deceived than that I should not?   
  Considering this more attentively, the first thing that occurs to me  
is the reflection that I must not be surprised if I am not always   
capable of comprehending the reasons why God acts as he does; nor must  
I doubt of his existence because I find, perhaps, that there are    
several other things, besides the present respecting which I    
understand neither why nor how they were created by him; for,   
knowing already that my nature is extremely weak and limited, and that  
the nature of God, on the other hand, is immense, incomprehensible, 
and infinite, I have no longer any difficulty in discerning that there  
is an infinity of things in his power whose causes transcend the grasp  
of my mind: and this consideration alone is sufficient to convince me,  
that the whole class of final causes is of no avail in physical [or 
natural] things; for it appears to me that I cannot, without    
exposing myself to the charge of temerity, seek to discover the 
[impenetrable] ends of Deity.   
  It further occurs to me that we must not consider only one    
creature apart from the others, if we wish to determine the perfection  
of the works of Deity, but generally all his creatures together; for    
the same object that might perhaps, with some show of reason, be    
deemed highly imperfect if it were alone in the world, may for all  
that be the most perfect possible, considered as forming part of the    
whole universe: and although, as it was my purpose to doubt of  
everything, I only as yet know with certainly my own existence and  
that of God, nevertheless, after having remarked the infinite power of  
Deity, I cannot deny that he may have produced many other objects,  
or at least that he is able to produce them, so that I may occupy a 
place in the relation of a part to the great whole of his creatures.    
  Whereupon, regarding myself more closely, and considering what my 
errors are (which alone testify to the existence of imperfection in 
me), I observe that these depend on the concurrence of two causes,  
viz., the faculty of cognition which I possess, and that of election    
or the power of free choice,- in other words, the understanding and 
the will. For by the understanding alone, I [neither affirm nor deny    
anything, but] merely apprehend (percipio) the ideas regarding which  
I may form a judgment; nor is any error, properly so called, found  
in it thus accurately taken. And although there are perhaps 
innumerable objects in the world of which I have no idea in my  
understanding, it cannot, on that account, be said that I am    
deprived of those ideas [as of something that is due to my nature], 
but simply that I do not possess them, because, in truth, there is  
no ground to prove that Deity ought to have endowed me with a larger    
faculty of cognition than he has actually bestowed upon me; and 
however skilful a workman I suppose him to be, I have no reason, on 
that account, to think that it was obligatory on him to give to each    
of his works all the perfections he is able to bestow upon some.    
Nor, moreover, can I complain that God has not given me freedom of  
choice, or a will sufficiently ample and perfect, since, in truth, I    
am conscious of will so ample and extended as to be superior to all 
limits. And what appears to me here to be highly remarkable is that,    
of all the other properties I possess, there is none so great and   
perfect as that I do not clearly discern it could be still greater and  
more perfect. For, to take an example, if I consider the faculty of 
understanding which I possess, I find that it is of very small extent,  
and greatly limited, and at the same time I form the idea of another    
faculty of the same nature, much more ample and even infinite; and  
seeing that I can frame the idea of it, I discover, from this   
circumstance alone, that it pertains to the nature of God. In the same  
way, if I examine the faculty of memory or imagination, or any other    
faculty I possess, I find none that is not small and circumscribed, 
and in God immense [and infinite]. It is the faculty of will only,  
or freedom of choice, which I experience to be so great that I am   
unable to conceive the idea of another that shall be more ample and 
extended; so that it is chiefly my will which leads me to discern that  
I bear a certain image and similitude of Deity. For although the    
faculty of will is incomparably greater in God than in myself, as well  
in respect of the knowledge and power that are conjoined with it,   
and that render it stronger and more efficacious, as in respect of the  
object, since in him it extends to a greater number of things, it does  
not, nevertheless, appear to me greater, considered in itself formally  
and precisely: for the power of will consists only in this, that we 
are able to do or not to do the same thing (that is, to affirm or   
deny, to pursue or shun it), or rather in this alone, that in   
affirming or denying, pursuing or shunning, what is proposed to us  
by the understanding, we so act that we are not conscious of being  
determined to a particular action by any external force. For, to the    
possession of freedom, it is not necessary that I be alike indifferent  
towards each of two contraries; but, on the contrary, the more I am 
inclined towards the one, whether because I clearly know that in it 
there is the reason of truth and goodness, or because God thus  
internally disposes my thought, the more freely do I choose and 
embrace it; and assuredly divine grace and natural knowledge, very far  
from diminishing liberty, rather augment and fortify it. But the    
indifference of which I am conscious when I am not impelled to one  
side rather than to another for want of a reason, is the lowest 
grade of liberty, and manifests defect or negation of knowledge rather  
than perfection, of will; for if I always clearly knew what was true    
and good, I should never have any difficulty in determining what    
judgment I ought to come to, and what choice I ought to make, and I 
should thus be entirely free without ever being indifferent.    
  From all this I discover, however, that neither the power of  
willing, which I have received from God, is of itself the source of my  
errors, for it is exceedingly ample and perfect in its kind; nor    
even the power of understanding, for as I conceive no object unless by  
means of the faculty that God bestowed upon me, all that I conceive is  
doubtless rightly conceived by me, and it is impossible for me to be    
deceived in it. 
  Whence, then, spring my errors? They arise from this cause alone, 
that I do not restrain the will, which is of much wider range than the  
understanding, within the same limits, but extend it even to things 
I do not understand, and as the will is of itself indifferent to such,  
it readily falls into error and sin by choosing the false in room of    
the true, and evil instead of good. 
  For example, when I lately considered whether aught really existed    
in the world, and found that because I considered this question, it 
very manifestly followed that I myself existed, I could not but 
judge that what I so clearly conceived was true, not that I was forced  
to this judgment by any external cause, but simply because great    
clearness of the understanding was succeeded by strong inclination  
in the will; and I believed this the more freely and spontaneously  
in proportion as I was less indifferent with respect to it. But now 
I not only know that I exist, in so far as I am a thinking being,   
but there is likewise presented to my mind a certain idea of corporeal  
nature; hence I am in doubt as to whether the thinking nature which is  
in me, or rather which I myself am, is different from that corporeal    
nature, or whether both are merely one and the same thing, and I    
here suppose that I am as yet ignorant of any reason that would 
determine me to adopt the one belief in preference to the other:    
whence it happens that it is a matter of perfect indifference to me 
which of the two suppositions I affirm or deny, or whether I form   
any judgment at all in the matter.  
  This indifference, moreover, extends not only to things of which the  
understanding has no knowledge at all, but in general also to all   
those which it does not discover with perfect clearness at the  
moment the will is deliberating upon them; for, however probable the    
conjectures may be that dispose me to form a judgment in a  
particular matter, the simple knowledge that these are merely   
conjectures, and not certain and indubitable reasons, is sufficient to  
lead me to form one that is directly the opposite. Of this I lately 
had abundant experience, when I laid aside as false all that I had  
before held for true, on the single ground that I could in some degree  
doubt of it. But if I abstain from judging of a thing when I do not 
conceive it with sufficient clearness and distinctness, it is plain 
that I act rightly, and am not deceived; but if I resolve to deny or    
affirm, I then do not make a right use of my free will; and if I    
affirm what is false, it is evident that I am deceived: moreover, even  
although I judge according to truth, I stumble upon it by chance,   
and do not therefore escape the imputation of a wrong use of my 
freedom; for it is a dictate of the natural light, that the 
knowledge of the understanding ought always to precede the  
determination of the will.  
  And it is this wrong use of freedom of the will in which is found 
the privation that constitutes the form of error. Privation, I say, is  
found in the act, in so far as it proceeds from myself, but it does 
not exist in the faculty which I received from God, nor even in the 
act, in so far as it depends on him; for I have assuredly no reason to  
complain that God has not given me a greater power of intelligence  
or more perfect natural light than he has actually bestowed, since  
it is of the nature of a finite understanding not to comprehend many    
things, and of the nature of a created understanding to be finite;  
on the contrary, I have every reason to render thanks to God, who owed  
me nothing, for having given me all the perfections I possess, and I    
should be far from thinking that he has unjustly deprived me of, or 
kept back, the other perfections which he has not bestowed upon me. 
  I have no reason, moreover, to complain because he has given me a 
will more ample than my understanding, since, as the will consists  
only of a single element, and that indivisible, it would appear that    
this faculty is of such a nature that nothing could be taken from it    
[without destroying it]; and certainly, the more extensive it is,   
the more cause I have to thank the goodness of him who bestowed it  
upon me.    
  And, finally, I ought not also to complain that God concurs with  
me in forming the acts of this will, or the judgments in which I am 
deceived, because those acts are wholly true and good, in so far as 
they depend on God; and the ability to form them is a higher degree of  
perfection in my nature than the want of it would be. With regard to    
privation, in which alone consists the formal reason of error and sin,  
this does not require the concurrence of Deity, because it is not a 
thing [or existence], and if it be referred to God as to its cause, it  
ought not to be called privation, but negation [according to the    
signification of these words in the schools]. For in truth it is no 
imperfection in Deity that he has accorded to me the power of giving    
or withholding my assent from certain things of which he has not put a  
clear and distinct knowledge in my understanding; but it is 
doubtless an imperfection in me that I do not use my freedom aright,    
and readily give my judgment on matters which I only obscurely and  
confusedly conceive.    
  I perceive, nevertheless, that it was easy for Deity so to have   
constituted me as that I should never be deceived, although I still 
remained free and possessed of a limited knowledge, viz., by    
implanting in my understanding a clear and distinct knowledge of all    
the objects respecting which I should ever have to deliberate; or   
simply by so deeply engraving on my memory the resolution to judge  
of nothing without previously possessing a clear and distinct   
conception of it, that I should never forget it. And I easily   
understand that, in so far as I consider myself as a single whole,  
without reference to any other being in the universe, I should have 
been much more perfect than I now am, had Deity created me superior to  
error; but I cannot therefore deny that it is not somehow a greater 
perfection in the universe, that certain of its parts are not exempt    
from defect, as others are, than if they were all perfectly alike.  
  And I have no right to complain because God, who placed me in the 
world, was not willing that I should sustain that character which of    
all others is the chief and most perfect; I have even good reason to    
remain satisfied on the ground that, if he has not given me the 
perfection of being superior to error by the first means I have 
pointed out above, which depends on a clear and evident knowledge of    
all the matters regarding which I can deliberate, he has at least left  
in my power the other means, which is, firmly to retain the resolution  
never to judge where the truth is not clearly known to me: for, 
although I am conscious of the weakness of not being able to keep my    
mind continually fixed on the same thought, I can nevertheless, by  
attentive and oft-repeated meditation, impress it so strongly on my 
memory that I shall never fail to recollect it as often as I require    
it, and I can acquire in this way the habitude of not erring; and   
since it is in being superior to error that the highest and chief   
perfection of man consists, I deem that I have not gained little by 
this day's meditation, in having discovered the source of error and 
  And certainly this can be no other than what I have now explained:    
for as often as I so restrain my will within the limits of my   
knowledge, that it forms no judgment except regarding objects which 
are clearly and distinctly represented to it by the understanding, I    
can never be deceived; because every clear and distinct conception  
is doubtless something, and as such cannot owe its origin to    
nothing, but must of necessity have God for its author- God, I say, 
who, as supremely perfect, cannot, without a contradiction, be the  
cause of any error; and consequently it is necessary to conclude    
that every such conception [or judgment] is true. Nor have I merely 
learned to-day what I must avoid to escape error, but also what I must  
do to arrive at the knowledge of truth; for I will assuredly reach  
truth if I only fix my attention sufficiently on all the things I   
conceive perfectly, and separate these from others which I conceive 
more confusedly and obscurely: to which for the future I shall give 
diligent heed.  

                             MEDITATION V   
                        OF GOD; THAT HE EXISTS    

  SEVERAL other questions remain for consideration respecting the   
attributes of God and my own nature or mind. I will, however, on    
some other occasion perhaps resume the investigation of these.  
Meanwhile, as I have discovered what must be done, and what avoided to  
arrive at the knowledge of truth, what I have chiefly to do is to   
essay to emerge from the state of doubt in which I have for some    
time been, and to discover whether anything can be known with   
certainty regarding material objects. But before considering whether    
such objects as I conceive exist without me, I must examine their   
ideas in so far as these are to be found in my consciousness, and   
discover which of them are distinct and which confused. 
  In the first place, I distinctly imagine that quantity which the  
philosophers commonly call continuous, or the extension in length,  
breadth, and depth that is in this quantity, or rather in the object    
to which it is attributed. Further, I can enumerate in it many diverse  
parts, and attribute to each of these all sorts of sizes, figures,  
situations, and local motions; and, in fine, I can assign to each of    
these motions all degrees of duration. And I not only distinctly    
know these things when I thus consider them in general; but besides,    
by a little attention, I discover innumerable particulars respecting    
figures, numbers, motion, and the like, which are so evidently true,    
and so accordant with my nature, that when I now discover them I do 
not so much appear to learn anything new, as to call to remembrance 
what I before knew, or for the first time to remark what was before in  
my mind, but to which I had not hitherto directed my attention. And 
what I here find of most importance is, that I discover in my mind  
innumerable ideas of certain objects, which cannot be esteemed pure 
negations, although perhaps they possess no reality beyond my thought,  
and which are not framed by me though it may be in my power to  
think, or not to think them, but possess true and immutable natures of  
their own. As, for example, when I imagine a triangle, although 
there is not perhaps and never was in any place in the universe 
apart from my thought one such figure, it remains true nevertheless 
that this figure possesses a certain determinate nature, form, or   
essence, which is immutable and eternal, and not framed by me, nor  
in any degree dependent on my thought; as appears from the  
circumstance, that diverse properties of the triangle may be    
demonstrated, viz., that its three angles are equal to two right, that  
its greatest side is subtended by its greatest angle, and the like, 
which, whether I will or not, I now clearly discern to belong to it,    
although before I did not at all think of them, when, for the first 
time, I imagined a triangle, and which accordingly cannot be said to    
have been invented by me. Nor is it a valid objection to allege,    
that perhaps this idea of a triangle came into my mind by the medium    
of the senses, through my having seen bodies of a triangular figure;    
for I am able to form in thought an innumerable variety of figures  
with regard to which it cannot be supposed that they were ever objects  
of sense, and I can nevertheless demonstrate diverse properties of  
their nature no less than of the triangle, all of which are 
assuredly true since I clearly conceive them; and they are therefore    
something, and not mere negations; for it is highly evident that all    
that is true is something [truth being identical with existence];   
and I have already fully shown the truth of the principle, that 
whatever is clearly and distinctly known is true. And although this 
had not been demonstrated, yet the nature of my mind is such as to  
compel me to assent to what I clearly conceive while I so conceive it;  
and I recollect that even when I still strongly adhered to the objects  
of sense, I reckoned among the number of the most certain truths those  
I clearly conceived relating to figures, numbers, and other matters 
that pertain to arithmetic and geometry, and in general to the pure 
  But now if because I can draw from my thought the idea of an object,  
it follows that all I clearly and distinctly apprehend to pertain to    
this object, does in truth belong to it, may I not from this derive an  
argument for the existence of God? It is certain that I no less find    
the idea of a God in my consciousness, that is, the idea of a being 
supremely perfect, than that of any figure or number whatever: and I    
know with not less clearness and distinctness that an [actual and]  
eternal existence pertains to his nature than that all which is 
demonstrable of any figure or number really belongs to the nature of    
that figure or number; and, therefore, although all the conclusions of  
the preceding Meditations were false, the existence of God would    
pass with me for a truth at least as certain as I ever judged any   
truth of mathematics to be, although indeed such a doctrine may at  
first sight appear to contain more sophistry than truth. For, as I  
have been accustomed in every other matter to distinguish between   
existence and essence, I easily believe that the existence can be   
separated from the essence of God, and that thus God may be 
conceived as not actually existing. But, nevertheless, when I think of  
it more attentively, it appears that the existence can no more be   
separated from the essence of God than the idea of a mountain from  
that of a valley, or the equality of its three angles to two right  
angles, from the essence of a [rectilineal] triangle; so that it is 
not less impossible to conceive a God, that is, a being supremely   
perfect, to whom existence is awanting, or who is devoid of a   
certain perfection, than to conceive a mountain without a valley.   
  But though, in truth, I cannot conceive a God unless as existing, 
any more than I can a mountain without a valley, yet, just as it    
does not follow that there is any mountain in the world merely because  
I conceive a mountain with a valley, so likewise, though I conceive 
God as existing, it does not seem to follow on that account that God    
exists; for my thought imposes no necessity on things; and as I may 
imagine a winged horse, though there be none such, so I could   
perhaps attribute existence to God, though no God existed. But the  
cases are not analogous, and a fallacy lurks under the semblance of 
this objection: for because I cannot conceive a mountain without a  
valley, it does not follow that there is any mountain or valley in  
existence, but simply that the mountain or valley, whether they do  
or do not exist, are inseparable from each other; whereas, on the   
other hand, because I cannot conceive God unless as existing, it    
follows that existence is inseparable from him, and therefore that  
he really exists: not that this is brought about by my thought, or  
that it imposes any necessity on things, but, on the contrary, the  
necessity which lies in the thing itself, that is, the necessity of 
the existence of God, determines me to think in this way, for it is 
not in my power to conceive a God without existence, that is a being    
supremely perfect, and yet devoid of an absolute perfection, as I am    
free to imagine a horse with or without wings.  
  Nor must it be alleged here as an objection, that it is in truth  
necessary to admit that God exists, after having supposed him to    
possess all perfections, since existence is one of them, but that my    
original supposition was not necessary; just as it is not necessary to  
think that all quadrilateral figures can be inscribed in the circle,    
since, if I supposed this, I should be constrained to admit that the    
rhombus, being a figure of four sides, can be therein inscribed,    
which, however, is manifestly false. This objection is, I say,  
incompetent; for although it may not be necessary that I shall at   
any time entertain the notion of Deity, yet each time I happen to   
think of a first and sovereign being, and to draw, so to speak, the 
idea of him from the store-house of the mind, I am necessitated to  
attribute to him all kinds of perfections, though I may not then    
enumerate them all, nor think of each of them in particular. And    
this necessity is sufficient, as soon as I discover that existence  
is a perfection, to cause me to infer the existence of this first   
and sovereign being; just as it is not necessary that I should ever 
imagine any triangle, but whenever I am desirous of considering a   
rectilineal figure composed of only three angles, it is absolutely  
necessary to attribute those properties to it from which it is  
correctly inferred that its three angles are not greater than two   
right angles, although perhaps I may not then advert to this    
relation in particular. But when I consider what figures are capable    
of being inscribed in the circle, it is by no means necessary to    
hold that all quadrilateral figures are of this number; on the  
contrary, I cannot even imagine such to be the case, so long as I   
shall be unwilling to accept in thought aught that I do not clearly 
and distinctly conceive: and consequently there is a vast difference    
between false suppositions, as is the one in question, and the true 
ideas that were born with me, the first and chief of which is the idea  
of God. For indeed I discern on many grounds that this idea is not  
factitious, depending simply on my thought, but that it is the  
representation of a true and immutable nature: in the first place,  
because I can conceive no other being, except God, to whose essence 
existence [necessarily] pertains; in the second, because it is  
impossible to conceive two or more gods of this kind; and it being  
supposed that one such God exists, I clearly see that he must have  
existed from all eternity, and will exist to all eternity; and  
finally, because I apprehend many other properties in God, none of  
which I can either diminish or change.  
  But, indeed, whatever mode of probation I in the end adopt, it    
always returns to this, that it is only the things I clearly and    
distinctly conceive which have the power of completely persuading   
me. And although, of the objects I conceive in this manner, some,   
indeed, are obvious to every one, while others are only discovered  
after close and careful investigation; nevertheless, after they are 
once discovered, the latter are not esteemed less certain than the  
former. Thus, for example, to take the case of a right-angled   
triangle, although it is not so manifest at first that the square of    
the base is equal to the squares of the other two sides, as that the    
base is opposite to the greatest angle; nevertheless, after it is once  
apprehended, we are as firmly persuaded of the truth of the former  
as of the latter. And, with respect to God, if I were not   
preoccupied by prejudices, and my thoughts beset on all sides by the    
continual presence of the images of sensible objects, I should know 
nothing sooner or more easily than the fact of his being. For is there  
any truth more clear than the existence of a Supreme Being, or of God,  
seeing it is to his essence alone that [necessary and eternal]  
existence pertains? And although the right conception of this truth 
has cost me much close thinking, nevertheless at present I feel not 
only as assured of it as of what I deem most certain, but I remark  
further that the certitude of all other truths is so absolutely 
dependent on it, that without this knowledge it is impossible ever  
to know anything perfectly. 
  For although I am of such a nature as to be unable, while I   
possess a very clear and distinct apprehension of a matter, to  
resist the conviction of its truth, yet because my constitution is  
also such as to incapacitate me from keeping my mind continually fixed  
on the same object, and as I frequently recollect a past judgment   
without at the same time being able to recall the grounds of it, it 
may happen meanwhile that other reasons are presented to me which   
would readily cause me to change my opinion, if I did not know that 
God existed; and thus I should possess no true and certain  
knowledge, but merely vague and vacillating opinions. Thus, for 
example, when I consider the nature of the [rectilineal] triangle,  
it most clearly appears to me, who have been instructed in the  
principles of geometry, that its three angles are equal to two right    
angles, and I find it impossible to believe otherwise, while I apply    
my mind to the demonstration; but as soon as I cease from attending to  
the process of proof, although I still remember that I had a clear  
comprehension of it, yet I may readily come to doubt of the truth   
demonstrated, if I do not know that there is a God: for I may persuade  
myself that I have been so constituted by nature as to be sometimes 
deceived, even in matters which I think I apprehend with the    
greatest evidence and certitude, especially when I recollect that I 
frequently considered many things to be true and certain which other    
reasons afterwards constrained me to reckon as wholly false.    
  But after I have discovered that God exists, seeing I also at the 
same time observed that all things depend on him, and that he is no 
deceiver, and thence inferred that all which I clearly and  
distinctly perceive is of necessity true: although I no longer  
attend to the grounds of a judgment, no opposite reason can be alleged  
sufficient to lead me to doubt of its truth, provided only I    
remember that I once possessed a clear and distinct comprehension of    
it. My knowledge of it thus becomes true and certain. And this same 
knowledge extends likewise to whatever I remember to have formerly  
demonstrated, as the truths of geometry and the like: for what can  
be alleged against them to lead me to doubt of them? Will it be that    
my nature is such that I may be frequently deceived? But I already  
know that I cannot be deceived in judgments of the grounds of which 
I possess a clear knowledge. Will it be that I formerly deemed  
things to be true and certain which I afterwards discovered to be   
false? But I had no clear and distinct knowledge of any of those    
things, and, being as yet ignorant of the rule by which I am assured    
of the truth of a judgment, I was led to give my assent to them on  
grounds which I afterwards discovered were less strong than at the  
time I imagined them to be. What further objection, then, is there? 
Will it be said that perhaps I am dreaming (an objection I lately   
myself raised), or that all the thoughts of which I am now conscious    
have no more truth than the reveries of my dreams? But although, in 
truth, I should be dreaming, the rule still holds that all which is 
clearly presented to my intellect is indisputably true. 
  And thus I very clearly see that the certitude and truth of all   
science depends on the knowledge alone of the true God, insomuch that,  
before I knew him, I could have no perfect knowledge of any other   
thing. And now that I know him, I possess the means of acquiring a  
perfect knowledge respecting innumerable matters, as well relative  
to God himself and other intellectual objects as to corporeal   
nature, in so far as it is the object of pure mathematics [which do 
not consider whether it exists or not]. 

                            MEDITATION VI   

  THERE now only remains the inquiry as to whether material things  
exist. With regard to this question, I at least know with certainty 
that such things may exist, in as far as they constitute the object of  
the pure mathematics, since, regarding them in this aspect, I can   
conceive them clearly and distinctly. For there can be no doubt that    
God possesses the power of producing all the objects I am able  
distinctly to conceive, and I never considered anything impossible  
to him, unless when I experienced a contradiction in the attempt to 
conceive it aright. Further, the faculty of imagination which I 
possess, and of which I am conscious that I make use when I apply   
myself to the consideration of material things, is sufficient to    
persuade me of their existence: for, when I attentively consider    
what imagination is, I find that it is simply a certain application of  
the cognitive faculty (facultas cognoscitiva) to a body which is  
immediately present to it, and which therefore exists.  
  And to render this quite clear, I remark, in the first place, the 
difference that subsists between imagination and pure intellection [or  
conception]. For example, when I imagine a triangle I not only  
conceive (intelligo) that it is a figure comprehended by three    
lines, but at the same time also I look upon (intueor) these three    
lines as present by the power and internal application of my mind   
(acie mentis), and this is what I call imagining. But if I desire to  
think of a chiliogon, I indeed rightly conceive that it is a figure 
composed of a thousand sides, as easily as I conceive that a    
triangle is a figure composed of only three sides; but I cannot 
imagine the thousand sides of a chiliogon as I do the three sides of a  
triangle, nor, so to speak, view them as present [with the eyes of  
my mind]. And although, in accordance with the habit I have of  
always imagining something when I think of corporeal things, it may 
happen that, in conceiving a chiliogon, I confusedly represent some 
figure to myself, yet it is quite evident that this is not a    
chiliogon, since it in no wise differs from that which I would  
represent to myself, if I were to think of a myriogon, or any other 
figure of many sides; nor would this representation be of any use in    
discovering and unfolding the properties that constitute the    
difference between a chiliogon and other polygons. But if the question  
turns on a pentagon, it is quite true that I can conceive its   
figure, as well as that of a chiliogon, without the aid of  
imagination; but I can likewise imagine it by applying the attention    
of my mind to its five sides, and at the same time to the area which    
they contain. Thus I observe that a special effort of mind is   
necessary to the act of imagination, which is not required to   
conceiving or understanding (ad intelligendum); and this special  
exertion of mind clearly shows the difference between imagination   
and pure intellection (imaginatio et intellectio pura). I remark, 
besides, that this power of imagination which I possess, in as far  
as it differs from the power of conceiving, is in no way necessary  
to my [nature or] essence, that is, to the essence of my mind; for  
although I did not possess it, I should still remain the same that I    
now am, from which it seems we may conclude that it depends on  
something different from the mind. And I easily understand that, if 
some body exists, with which my mind is so conjoined and united as  
to be able, as it were, to consider it when it chooses, it may thus 
imagine corporeal objects; so that this mode of thinking differs    
from pure intellection only in this respect, that the mind in   
conceiving turns in some way upon itself, and considers some one of 
the ideas it possesses within itself; but in imagining it turns 
towards the body, and contemplates in it some object conformed to   
the idea which it either of itself conceived or apprehended by  
sense. I easily understand, I say, that imagination may be thus 
formed, if it is true that there are bodies; and because I find no  
other obvious mode of explaining it, I thence, with probability,    
conjecture that they exist, but only with probability; and although 
I carefully examine all things, nevertheless I do not find that,    
from the distinct idea of corporeal nature I have in my imagination, I  
can necessarily infer the existence of any body.    
  But I am accustomed to imagine many other objects besides that    
corporeal nature which is the object of the pure mathematics, as,   
for example, colours, sounds, tastes, pain, and the like, although  
with less distinctness; and, inasmuch as I perceive these objects much  
better by the senses, through the medium of which and of memory,    
they seem to have reached the imagination, I believe that, in order 
the more advantageously to examine them, it is proper I should at   
the same time examine what sense-perception is, and inquire whether 
from those ideas that are apprehended by this mode of thinking  
(consciousness), I cannot obtain a certain proof of the existence of    
corporeal objects.  
  And, in the first place, I will recall to my mind the things I    
have hitherto held as true, because perceived by the senses, and the    
foundations upon which my belief in their truth rested; I will, in the  
second place, examine the reasons that afterwards constrained me to 
doubt of them; and, finally, I will consider what of them I ought   
now to believe. 
  Firstly, then, I perceived that I had a head, hands, feet, and other  
members composing that body which I considered as part, or perhaps  
even as the whole, of myself. I perceived further, that that body   
was placed among many others, by which it was capable of being  
affected in diverse ways, both beneficial and hurtful; and what was 
beneficial I remarked by a certain sensation of pleasure, and what was  
hurtful by a sensation of pain. And, besides this pleasure and pain, I  
was likewise conscious of hunger, thirst, and other appetites, as well  
as certain corporeal inclinations towards joy, sadness, anger, and  
similar passions. And, out of myself, besides the extension, figure,    
and motions of bodies, I likewise perceived in them hardness, heat, 
and the other tactile qualities, and, in addition, light, colours,  
odours, tastes, and sounds, the variety of which gave me the means  
of distinguishing the sky, the earth, the sea, and generally all the    
other bodies, from one another. And certainly, considering the ideas    
of all these qualities, which were presented to my mind, and which  
alone I properly and immediately perceived, it was not without  
reason that I thought I perceived certain objects wholly different  
from my thought, namely, bodies from which those ideas proceeded;   
for I was conscious that the ideas were presented to me without my  
consent being required, so that I could not perceive any object,    
however desirous I might be, unless it were present to the organ of 
sense; and it was wholly out of my power not to perceive it when it 
was thus present. And because the ideas I perceived by the senses were  
much more lively and clear, and even, in their own way, more    
distinct than any of those I could of myself frame by meditation, or    
which I found impressed on my memory, it seemed that they could not 
have proceeded from myself, and must therefore have been caused in  
me by some other objects: and as of those objects I had no knowledge    
beyond what the ideas themselves gave me, nothing was so likely to  
occur to my mind as the supposition that the objects were similar to    
the ideas which they caused. And because I recollected also that I had  
formerly trusted to the senses, rather than to reason, and that the 
ideas which I myself formed were not so clear as those I perceived  
by sense, and that they were even for the most part composed of 
parts of the latter, I was readily persuaded that I had no idea in  
my intellect which had not formerly passed through the senses. Nor was  
I altogether wrong in likewise believing that that body which, by a 
special right, I called my own, pertained to me more properly and   
strictly than any of the others; for in truth, I could never be 
separated from it as from other bodies: I felt in it and on account of  
it all my appetites and affections, and in fine I was affected in   
its parts by pain and the titillation of pleasure, and not in the   
parts of the other bodies that were separated from it. But when I   
inquired into the reason why, from this I know not what sensation of    
pain, sadness of mind should follow, and why from the sensation of  
pleasure joy should arise, or why this indescribable twitching of   
the stomach, which I call hunger, should put me in mind of taking   
food, and the parchedness of the throat of drink, and so in other   
cases, I was unable to give any explanation, unless that I was so   
taught by nature; for there is assuredly no affinity, at least none 
that I am able to comprehend, between this irritation of the stomach    
and the desire of food, any more than between the perception of an  
object that causes pain and the consciousness of sadness which springs  
from the perception. And in the same way it seemed to me that all   
the other judgments I had formed regarding the objects of sense,    
were dictates of nature; because I remarked that those judgments    
were formed in me, before I had leisure to weigh and consider the   
reasons that might constrain me to form them.   
  But, afterwards, a wide experience by degrees sapped the faith I had  
reposed in my senses; for I frequently observed that towers, which  
at a distance seemed round, appeared square when more closely   
viewed, and that colossal figures, raised on the summits of these   
towers, looked like small statues, when viewed from the bottom of   
them; and, in other instances without number, I also discovered 
error in judgments founded on the external senses; and not only in  
those founded on the external, but even in those that rested on the 
internal senses; for is there aught more internal than pain? and yet I  
have sometimes been informed by parties whose arm or leg had been   
amputated, that they still occasionally seemed to feel pain in that 
part of the body which they had lost,- a circumstance that led me to    
think that I could not be quite certain even that any one of my 
members was affected when I felt pain in it. And to these grounds of    
doubt I shortly afterwards also added two others of very wide   
generality: the first of them was that I believed I never perceived 
anything when awake which I could not occasionally think I also 
perceived when asleep, and as I do not believe that the ideas I seem    
to perceive in my sleep proceed from objects external to me, I did not  
any more observe any ground for believing this of such as I seem to 
perceive when awake; the second was that since I was as yet ignorant    
of the author of my being, or at least supposed myself to be so, I saw  
nothing to prevent my having been so constituted by nature as that I    
should be deceived even in matters that appeared to me to possess   
the greatest truth. And, with respect to the grounds on which I had 
before been persuaded of the existence of sensible objects, I had no    
great difficulty in finding suitable answers to them; for as nature 
seemed to incline me to many things from which reason made me   
averse, I thought that I ought not to confide much in its teachings.    
And although the perceptions of the senses were not dependent on my 
will, I did not think that I ought on that ground to conclude that  
they proceeded from things different from myself, since perhaps 
there might be found in me some faculty, though hitherto unknown to 
me, which produced them.    
  But now that I begin to know myself better, and to discover more  
clearly the author of my being, I do not, indeed, think that I ought    
rashly to admit all which the senses seem to teach, nor, on the 
other hand, is it my conviction that I ought to doubt in general of 
their teachings.    
  And, firstly, because I know that all which I clearly and distinctly  
conceive can be produced by God exactly as I conceive it, it is 
sufficient that I am able clearly and distinctly to conceive one thing  
apart from another, in order to be certain that the one is different    
from the other, seeing they may at least be made to exist   
separately, by the omnipotence of God; and it matters not by what   
power this separation is made, in order to be compelled to judge    
them different; and, therefore, merely because I know with certitude    
that I exist, and because, in the meantime, I do not observe that   
aught necessarily belongs to my nature or essence beyond my being a 
thinking thing, I rightly conclude that my essence consists only in my  
being a thinking thing [or a substance whose whole essence or nature    
is merely thinking]. And although I may, or rather, as I will   
shortly say, although I certainly do possess a body with which I am 
very closely conjoined; nevertheless, because, on the one hand, I have  
a clear and distinct idea of myself, in as far as I am only a thinking  
and unextended thing, and as, on the other hand, I possess a    
distinct idea of body, in as far as it is only an extended and  
unthinking thing, it is certain that I [that is, my mind, by which I    
am what I am] is entirely and truly distinct from my body, and may  
exist without it.   
  Moreover, I find in myself diverse faculties of thinking that have    
each their special mode: for example, I find I possess the faculties    
of imagining and perceiving, without which I can indeed clearly and 
distinctly conceive myself as entire, but I cannot reciprocally 
conceive them without conceiving myself, that is to say, without an 
intelligent substance in which they reside, for [in the notion we have  
of them, or to use the terms of the schools] in their formal    
concept, they comprise some sort of intellection; whence I perceive 
that they are distinct from myself as modes are from things. I  
remark likewise certain other faculties, as the power of changing   
place, of assuming diverse figures, and the like, that cannot be    
conceived and cannot therefore exist, any more than the preceding,  
apart from a substance in which they inhere. It is very evident,    
however, that these faculties, if they really exist, must belong to 
some corporeal or extended substance, since in their clear and  
distinct concept there is contained some sort of extension, but no  
intellection at all. Farther, I cannot doubt but that there is in me a  
certain passive faculty of perception, that is, of receiving and    
taking knowledge of the ideas of sensible things; but this would be 
useless to me, if there did not also exist in me, or in some other  
thing, another active faculty capable of forming and producing those    
ideas. But this active faculty cannot be in me [in as far as I am   
but a thinking thing], seeing that it does not presuppose thought, and  
also that those ideas are frequently produced in my mind without my 
contributing to it in any way, and even frequently contrary to my   
will. This faculty must therefore exist in some substance different 
from me, in which all the objective reality of the ideas that are   
produced by this faculty is contained formally or eminently, as I   
before remarked: and this substance is either a body, that is to    
say, a corporeal nature in which is contained formally [and in effect]  
all that is objectively [and by representation] in those ideas; or  
it is God himself, or some other creature, of a rank superior to body,  
in which the same is contained eminently. But as God is no deceiver,    
it is manifest that he does not of himself and immediately communicate  
those ideas to me, nor even by the intervention of any creature in  
which their objective reality is not formally, but only eminently,  
contained. For as he has given me no faculty whereby I can discover 
this to be the case, but, on the contrary, a very strong inclination    
to believe that those ideas arise from corporeal objects, I do not see  
how he could be vindicated from the charge of deceit, if in truth they  
proceeded from any other source, or were produced by other causes than  
corporeal things: and accordingly it must be concluded, that corporeal  
objects exist. Nevertheless they are not perhaps exactly such as we 
perceive by the senses, for their comprehension by the senses is, in    
many instances, very obscure and confused; but it is at least   
necessary to admit that all which I clearly and distinctly conceive as  
in them, that is, generally speaking, all that is comprehended in   
the object of speculative geometry, really exists external to me.   
  But with respect to other things which are either only particular,    
as, for example, that the sun is of such a size and figure, etc., or    
are conceived with less clearness and distinctness, as light, sound,    
pain, and the like, although they are highly dubious and uncertain, 
nevertheless on the ground alone that God is no deceiver, and that  
consequently he has permitted no falsity in my opinions which he has    
not likewise given me a faculty of correcting, I think I may with   
safety conclude that I possess in myself the means of arriving at   
the truth. And, in the first place, it cannot be doubted that in    
each of the dictates of nature there is some truth: for by nature,  
considered in general, I now understand nothing more than God himself,  
or the order and disposition established by God in created things; and  
by my nature in particular I understand the assemblage of all that God  
has given me. 
  But there is nothing which that nature teaches me more expressly [or  
more sensibly] than that I have a body which is ill affected when I 
feel pain, and stands in need of food and drink when I experience   
the sensations of hunger and thirst, etc. And therefore I ought not to  
doubt but that there is some truth in these informations.   
  Nature likewise teaches me by these sensations of pain, hunger,   
thirst, etc., that I am not only lodged in my body as a pilot in a  
vessel, but that I am besides so intimately conjoined, and as it    
were intermixed with it, that my mind and body compose a certain    
unity. For if this were not the case, I should not feel pain when my    
body is hurt, seeing I am merely a thinking thing, but should perceive  
the wound by the understanding alone, just as a pilot perceives by  
sight when any part of his vessel is damaged; and when my body has  
need of food or drink, I should have a clear knowledge of this, and 
not be made aware of it by the confused sensations of hunger and    
thirst: for, in truth, all these sensations of hunger, thirst, pain,    
etc., are nothing more than certain confused modes of thinking, 
arising from the union and apparent fusion of mind and body.    
  Besides this, nature teaches me that my own body is surrounded by 
many other bodies, some of which I have to seek after, and others to    
shun. And indeed, as I perceive different sorts of colours, sounds, 
odours, tastes, heat, hardness, etc., I safely conclude that there are  
in the bodies from which the diverse perceptions of the senses  
proceed, certain varieties corresponding to them, although, perhaps,    
not in reality like them; and since, among these diverse perceptions    
of the senses, some are agreeable, and others disagreeable, there   
can be no doubt that my body, or rather my entire self, in as far as I  
am composed of body and mind, may be variously affected, both   
beneficially and hurtfully, by surrounding bodies.  
  But there are many other beliefs which, though seemingly the  
teaching of nature, are not in reality so, but which obtained a 
place in my mind through a habit of judging inconsiderately of things.  
It may thus easily happen that such judgments shall contain error:  
thus, for example, the opinion I have that all space in which there is  
nothing to affect [or make an impression on] my senses is void; that    
in a hot body there is something in every respect similar to the    
idea of heat in my mind; that in a white or green body there is the 
same whiteness or greenness which I perceive; that in a bitter or   
sweet body there is the same taste, and so in other instances; that 
the stars, towers, and all distant bodies, are of the same size and 
figure as they appear to our eyes, etc. But that I may avoid    
everything like indistinctness of conception, I must accurately define  
what I properly understand by being taught by nature. For nature is 
here taken in a narrower sense than when it signifies the sum of all    
the things which God has given me; seeing that in that meaning the  
notion comprehends much that belongs only to the mind [to which I am    
not here to be understood as referring when I use the term nature]; 
as, for example, the notion I have of the truth, that what is done  
cannot be undone, and all the other truths I discern by the natural 
light [without the aid of the body]; and seeing that it comprehends 
likewise much besides that belongs only to body, and is not here any    
more contained under the name nature, as the quality of heaviness, and  
the like, of which I do not speak,- the term being reserved 
exclusively to designate the things which God has given to me as a  
being composed of mind and body. But nature, taking the term in the 
sense explained, teaches me to shun what causes in me the sensation of  
pain, and to pursue what affords me the sensation of pleasure, and  
other things of this sort; but I do not discover that it teaches me,    
in addition to this, from these diverse perceptions of the senses,  
to draw any conclusions respecting external objects without a previous  
[careful and mature] consideration of them by the mind: for it is,  
as appears to me, the office of the mind alone, and not of the  
composite whole of mind and body, to discern the truth in those 
matters. Thus, although the impression a star makes on my eye is not    
larger than that from the flame of a candle, I do not, nevertheless,    
experience any real or positive impulse determining me to believe that  
the star is not greater than the flame; the true account of the matter  
being merely that I have so judged from my youth without any    
rational ground. And, though on approaching the fire I feel heat,   
and even pain on approaching it too closely, I have, however, from  
this no ground for holding that something resembling the heat I feel    
is in the fire, any more than that there is something similar to the    
pain; all that I have ground for believing is, that there is something  
in it, whatever it may be, which excites in me those sensations of  
heat or pain. So also, although there are spaces in which I find    
nothing to excite and affect my senses, I must not therefore    
conclude that those spaces contain in them no body; for I see that  
in this, as in many other similar matters, I have been accustomed to    
pervert the order of nature, because these perceptions of the   
senses, although given me by nature merely to signify to my mind    
what things are beneficial and hurtful to the composite whole of which  
it is a part, and being sufficiently clear and distinct for that    
purpose, are nevertheless used by me as infallible rules by which to    
determine immediately the essence of the bodies that exist out of   
me, of which they can of course afford me only the most obscure and 
confused knowledge. 
  But I have already sufficiently considered how it happens that,   
notwithstanding the supreme goodness of God, there is falsity in my 
judgments. A difficulty, however, here presents itself, respecting the  
things which I am taught by nature must be pursued or avoided, and  
also respecting the internal sensations in which I seem to have 
occasionally detected error [and thus to be directly deceived by    
nature]: thus, for example, I may be so deceived by the agreeable   
taste of some viand with which poison has been mixed, as to be induced  
to take the poison. In this case, however, nature may be excused,   
for it simply leads me to desire the viand for its agreeable taste, 
and not the poison, which is unknown to it; and thus we can infer   
nothing from this circumstance beyond that our nature is not    
omniscient; at which there is assuredly no ground for surprise, since,  
man being of a finite nature, his knowledge must likewise be of 
limited perfection. But we also not unfrequently err in that to 
which we are directly impelled by nature, as is the case with invalids  
who desire drink or food that would be hurtful to them. It will 
here, perhaps, be alleged that the reason why such persons are  
deceived is that their nature is corrupted; but this leaves the 
difficulty untouched, for a sick man is not less really the creature    
of God than a man who is in full health; and therefore it is as 
repugnant to the goodness of God that the nature of the former  
should be deceitful as it is for that of the latter to be so. And,  
as a clock, composed of wheels and counter-weights, observes not the    
less accurately all the laws of nature when it is ill made, and points  
out the hours incorrectly, than when it satisfies the desire of the 
maker in every respect; so likewise if the body of man be considered    
as a kind of machine, so made up and composed of bones, nerves, 
muscles, veins, blood, and skin, that although there were in it no  
mind, it would still exhibit the same motions which it at present   
manifests involuntarily, and therefore without the aid of the mind  
[and simply by the dispositions of its organs], I easily discern    
that it would also be as natural for such a body, supposing it  
dropsical, for example, to experience the parchedness of the throat 
that is usually accompanied in the mind by the sensation of thirst, 
and to be disposed by this parchedness to move its nerves and its   
other parts in the way required for drinking, and thus increase its 
malady and do itself harm, as it is natural for it, when it is not  
indisposed to be stimulated to drink for its good by a similar  
cause; and although looking to the use for which a clock was    
destined by its maker, I may say that it is deflected from its  
proper nature when it incorrectly indicates the hours, and on the same  
principle, considering the machine of the human body as having been 
formed by God for the sake of the motions which it usually  
manifests, although I may likewise have ground for thinking that it 
does not follow the order of its nature when the throat is parched and  
drink does not tend to its preservation, nevertheless I yet plainly 
discern that this latter acceptation of the term nature is very 
different from the other; for this is nothing more than a certain   
denomination, depending entirely on my thought, and hence called    
extrinsic, by which I compare a sick man and an imperfectly 
constructed clock with the idea I have of a man in good health and a    
well-made clock; while by the other acceptation of nature is    
understood something which is truly found in things, and therefore  
possessed of some truth. 
  But certainly, although in respect of a dropsical body, it is only    
by way of exterior denomination that we say its nature is corrupted,    
when, without requiring drink, the throat is parched; yet, in   
respect of the composite whole, that is, of the mind in its union with  
the body, it is not a pure denomination, but really an error of 
nature, for it to feel thirst when drink would be hurtful to it:    
and, accordingly, it still remains to be considered why it is that the  
goodness of God does not prevent the nature of man thus taken from  
being fallacious.  
  To commence this examination accordingly, I here remark, in the   
first place, that there is a vast difference between mind and body, in  
respect that body, from its nature, is always divisible, and that mind  
is entirely indivisible. For in truth, when I consider the mind,    
that is, when I consider myself in so far only as I am a thinking   
thing, I can distinguish in myself no parts, but I very clearly 
discern that I am somewhat absolutely one and entire; and although the  
whole mind seems to be united to the whole body, yet, when a foot,  
an arm, or any other part is cut off, I am conscious that nothing   
has been taken from my mind; nor can the faculties of willing,  
perceiving, conceiving, etc., properly be called its parts, for it  
is the same mind that is exercised [all entire] in willing, in  
perceiving, and in conceiving, etc. But quite the opposite holds in 
corporeal or extended things; for I cannot imagine any one of them  
[how small soever it may be], which I cannot easily sunder in thought,  
and which, therefore, I do not know to be divisible. This would be  
sufficient to teach me that the mind or soul of man is entirely 
different from the body, if I had not already been apprised of it on    
other grounds.  
  I remark, in the next place, that the mind does not immediately   
receive the impression from all the parts of the body, but only from    
the brain, or perhaps even from one small part of it, viz., that in 
which the common sense (sensus communis) is said to be, which as  
often as it is affected in the same way, gives rise to the same 
perception in the mind, although meanwhile the other parts of the body  
may be diversely disposed, as is proved by innumerable experiments, 
which it is unnecessary here to enumerate.  
  I remark, besides, that the nature of body is such that none of   
its parts can be moved by another part a little removed from the    
other, which cannot likewise be moved in the same way by any one of 
the parts that lie between those two, although the most remote part 
does not act at all. As, for example, in the cord A, B, C, D [which is  
in tension], if its last part D be pulled, the first part A will not    
be moved in a different way than it would be were one of the    
intermediate parts B or C to be pulled, and the last part D 
meanwhile to remain fixed. And in the same way, when I feel pain in 
the foot, the science of physics teaches me that this sensation is  
experienced by means of the nerves dispersed over the foot, which,  
extending like cords from it to the brain, when they are contracted in  
the foot, contract at the same time the inmost parts of the brain in    
which they have their origin, and excite in these parts a certain   
motion appointed by nature to cause in the mind a sensation of pain,    
as if existing in the foot: but as these nerves must pass through   
the tibia, the leg, the loins, the back, and neck, in order to reach    
the brain, it may happen that although their extremities in the foot    
are not affected, but only certain of their parts that pass through 
the loins or neck, the same movements, nevertheless, are excited in 
the brain by this motion as would have been caused there by a hurt  
received in the foot, and hence the mind will necessarily feel pain in  
the foot, just as if it had been hurt; and the same is true of all the  
other perceptions of our senses.  
  I remark, finally, that as each of the movements that are made in 
the part of the brain by which the mind is immediately affected,    
impresses it with but a single sensation, the most likely   
supposition in the circumstances is, that this movement causes the  
mind to experience, among all the sensations which it is capable of 
impressing upon it, that one which is the best fitted, and generally    
the most useful for the preservation of the human body when it is in    
full health. But experience shows us that all the perceptions which 
nature has given us are of such a kind as I have mentioned; and 
accordingly, there is nothing found in them that does not manifest the  
power and goodness of God. Thus, for example, when the nerves of the    
foot are violently or more than usually shaken, the motion passing  
through the medulla of the spine to the innermost parts of the brain    
affords a sign to the mind on which it experiences a sensation, 
viz., of pain, as if it were in the foot, by which the mind is  
admonished and excited to do its utmost to remove the cause of it as    
dangerous and hurtful to the foot. It is true that God could have so    
constituted the nature of man as that the same motion in the brain  
would have informed the mind of something altogether different: the 
motion might, for example, have been the occasion on which the mind 
became conscious of itself, in so far as it is in the brain, or in  
so far as it is in some place intermediate between the foot and the 
brain, or, finally, the occasion on which it perceived some other   
object quite different, whatever that might be; but nothing of all  
this would have so well contributed to the preservation of the body as  
that which the mind actually feels. In the same way, when we stand  
in need of drink, there arises from this want a certain parchedness in  
the throat that moves its nerves, and by means of them the internal 
parts of the brain, and this movement affects the mind with the 
sensation of thirst, because there is nothing on that occasion which    
is more useful for us than to be made aware that we have need of drink  
for the preservation of our health; and so in other instances.  
  Whence it is quite manifest, that notwithstanding the sovereign   
goodness of God, the nature of man, in so far as it is composed of  
mind and body, cannot but be sometimes fallacious. For, if there is 
any cause which excites, not in the foot, but in some one of the parts  
of the nerves that stretch from the foot to the brain, or even in   
the brain itself, the same movement that is ordinarily created when 
the foot is ill affected, pain will be felt, as it were, in the 
foot, and the sense will thus be naturally deceived; for as the same    
movement in the brain can but impress the mind with the same    
sensation, and as this sensation is much more frequently excited by 
a cause which hurts the foot than by one acting in a different  
quarter, it is reasonable that it should lead the mind to feel pain in  
the foot rather than in any other part of the body. And if it   
sometimes happens that the parchedness of the throat does not arise,    
as is usual, from drink being necessary for the health of the body, 
but from quite the opposite cause, as is the case with the  
dropsical, yet it is much better that it should be deceitful in that    
instance, than if, on the contrary, it were continually fallacious  
when the body is well-disposed; and the same holds true in other    
  And certainly this consideration is of great service, not only in 
enabling me to recognise the errors to which my nature is liable,   
but likewise in rendering it more easy to avoid or correct them:    
for, knowing that all my senses more usually indicate to me what is 
true than what is false, in matters relating to the advantage of the    
body, and being able almost always to make use of more than a single    
sense in examining the same object, and besides this, being able to 
use my memory in connecting present with past knowledge, and my 
understanding which has already discovered all the causes of my 
errors, I ought no longer to fear that falsity may be met with in what  
is daily presented to me by the senses. And I ought to reject all   
the doubts of those bygone days as hyperbolical and ridiculous, 
especially the general uncertainty respecting sleep, which I could not  
distinguish from the waking state: for I now find a very marked 
difference between the two states, in respect that our memory can   
never connect our dreams with each other and with the course of 
life, in the way it is in the habit of doing with events that occur 
when we are awake. And, in truth, if some one, when I am awake, 
appeared to me all of a sudden and as suddenly disappeared, as do   
the images I see in sleep, so that I could not observe either whence    
he came or whither he went, I should not without reason esteem it   
either a spectre or phantom formed in my brain, rather than a real  
man. But when I perceive objects with regard to which I can distinctly  
determine both the place whence they come, and that in which they are,  
and the time at which they appear to me, and when, without  
interruption, I can connect the perception I have of them with the  
whole of the other parts of my life, I am perfectly sure that what I    
thus perceive occurs while I am awake and not during sleep. And I   
ought not in the least degree to doubt of the truth of those    
presentations, if, after having called together all my senses, my   
memory, and my understanding for the purpose of examining them, no  
deliverance is given by any one of these faculties which is 
repugnant to that of any other: for since God is no deceiver, it    
necessarily follows that I am not herein deceived. But because the  
necessities of action frequently oblige us to come to a 
determination before we have had leisure for so careful an  
examination, it must be confessed that the life of man is frequently    
obnoxious to error with respect to individual objects; and we must, in  
conclusion, acknowledge the weakness of our nature.