Meditations on First Philosophy.

by Rene Descartes.

TO THE MOST WISE AND ILl.u.s.tRIOUS THE DEAN AND DOCTORS OF THE SACRED FACULTY OF THEOLOGY IN PARIS.

The motive which induces me to present to you this Treatise is so excellent, and, when you become acquainted with its design, I am convinced that you will also have so excellent a motive for taking it under your protection, that I feel that I cannot do better, in order to render it in some sort acceptable to you, than in a few words to state what I have set myself to do.

I have always considered that the two questions respecting G.o.d and the Soul were the chief of those that ought to be demonstrated by philosophical rather than theological argument. For although it is quite enough for us faithful ones to accept by means of faith the fact that the human soul does not perish with the body, and that G.o.d exists, it certainly does not seem possible ever to persuade infidels of any religion, indeed, we may almost say, of any moral virtue, unless, to begin with, we prove these two facts by means of the natural reason. And inasmuch as often in this life greater rewards are offered for vice than for virtue, few people would prefer the right to the useful, were they restrained neither by the fear of G.o.d nor the expectation of another life; and although it is absolutely true that we must believe that there is a G.o.d, because we are so taught in the Holy Scriptures, and, on the other hand, that we must believe the Holy Scriptures because they come from G.o.d (the reason of this is, that, faith being a gift of G.o.d, He who gives the grace to cause us to believe other things can likewise give it to cause us to believe that He exists), we nevertheless could not place this argument before infidels, who might accuse us of reasoning in a circle. And, in truth, I have noticed that you, along with all the theologians, did not only affirm that the existence of G.o.d may be proved by the natural reason, but also that it may be inferred from the Holy Scriptures, that knowledge about Him is much clearer than that which we have of many created things, and, as a matter of fact, is so easy to acquire, that those who have it not are culpable in their ignorance. This indeed appears from the Wisdom of Solomon, chapter 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, chapter i., it is said that they are "without excuse"; and again in the same place, by these words "that which may be known of G.o.d is manifest in them," it seems as through we were shown that all that which can be known of G.o.d may be made manifest by means which are not derived from anywhere but from ourselves, and from the simple consideration of the nature of our minds.

Hence I thought it not beside my purpose to inquire how this is so, and how G.o.d may be more easily and certainly known than the things of the world.

And as regards the soul, although many have considered that it is not easy to know its nature, and some have even dared to say that human reasons have convinced us that it would perish with the body, and that faith alone could believe the contrary, nevertheless, inasmuch as the Lateran Council held under Leo X (in the eighth session) condemns these tenets, and as Leo expressly ordains Christian philosophers to refute their arguments and to employ all their powers in making known the truth, I have ventured in this treatise to undertake the same task.

More than that, I am aware that the princ.i.p.al reason which causes many impious persons not to desire to believe that there is a G.o.d, and that the human soul is distinct from the body, is that they declare that hitherto no one has been able to demonstrate these two facts; and although I am not of their opinion but, on the contrary, hold that the greater part of the reasons which have been brought forward concerning these two questions by so many great men are, when they are rightly understood, equal to so many demonstrations, and that it is almost impossible to invent new ones, it is yet in my opinion the case that nothing more useful can be accomplished in philosophy than once for all to seek with care for the best of these reasons, and to set them forth in so clear and exact a manner, that it will henceforth be evident to everybody that they are veritable demonstrations. And, finally, inasmuch as it was desired that I should undertake this task by many who were aware that I had cultivated a certain Method for the resolution of difficulties of every kind in the Sciencesa method which it is true is not novel, since there is nothing more ancient than the truth, but of which they were aware that I had made use successfully enough in other matters of difficultyI have thought that it was my duty also to make trial of it in the present matter.

Now all that I could accomplish in the matter is contained in this Treatise. Not that I have here drawn together all the different reasons which might be brought forward to serve as proofs of this subject: for that never seemed to be necessary excepting when there was no one single proof that was certain. But I have treated the first and princ.i.p.al ones in such a manner that I can venture to bring them forward as very evident and very certain demonstrations.

And more than that, I will say that these proofs are such that I do not think that there is any way open to the human mind by which it can ever succeed in discovering better. For the importance of the subject, and the glory of G.o.d to which all this relates, constrain me to speak here somewhat more freely of myself than is my habit. Nevertheless, whatever certainty and evidence I find in my reasons, I cannot persuade myself that all the world is capable of understanding them. Still, just as in Geometry there are many demonstrations that have been left to us by Archimedes, by Apollonius, by Pappus, and others, which are accepted by everyone as perfectly certain and evident (because they clearly contain nothing which, considered by itself, is not very easy to understand, and as all through that which follows has an exact connection with, and dependence on that which precedes), nevertheless, because they are somewhat lengthy, and demand a mind wholly devoted tot heir consideration, they are only taken in and understood by a very limited number of persons. Similarly, although I judge that those of which I here make use are equal to, or even surpa.s.s in certainty and evidence, the demonstrations of Geometry, I yet apprehend that they cannot be adequately understood by many, both because they are also a little lengthy and dependent the one on the other, and princ.i.p.ally because they demand a mind wholly free of prejudices, and one which can be easily detached from the affairs of the senses.

And, truth to say, there are not so many in the world who are fitted for metaphysical speculations as there are for those of Geometry. And more than that; there is still this difference, that in Geometry, since each one is persuaded that nothing must be advanced of which there is not a certain demonstration, those who are not entirely adepts more frequently err in approving what is false, in order to give the impression that they understand it, than in refuting the true. But the case is different in philosophy where everyone believes that all is problematical, and few give themselves to the search after truth; and the greater number, in their desire to acquire a reputation for boldness of thought, arrogantly combat the most important of truths.

That is why, whatever force there may be in my reasonings, seeing they belong to philosophy, I cannot hope that they will have much effect on the minds of men, unless you extend to them your protection. But the estimation in which you Company is universally held is so great, and the name of SORBONNE carries with it so much authority, that, next to the Sacred Councils, never has such deference been paid to the judgment of any Body, not only in what concerns the faith, but also in what regards human philosophy as well: everyone indeed believes that it is not possible to discover elsewhere more perspicacity and solidity, or more integrity and wisdom in p.r.o.nouncing judgment. For this reason I have no doubt that if you deign to take the trouble in the first place of correcting this work (for being conscious not only of my infirmity, but also of my ignorance, I should not dare to state that it was free from errors), and then, after adding to it these things that are lacking to it, completing those which are imperfect, and yourselves taking the trouble to give a more ample explanation of those things which have need of it, or at least making me aware of the defects so that I may apply myself to remedy them4 when this is done and when finally the reasonings by which I prove that there is a G.o.d, and that the human soul differs from the body, shall be carried to that point of perspicuity to which I am sure they can be carried in order that they may be esteemed as perfectly exact demonstrations, if you deign to authorize your approbation and to render public testimony to their truth and certainty, I do not doubt, I say, that henceforward all the errors and false opinions which have ever existed regarding these two questions will soon be effaced from the minds of men. For the truth itself will easily cause all men of mind and learning to subscribe to your judgment; and your authority will cause the atheists, who are usually more arrogant than learned or judicious, to rid themselves of their spirit of contradiction or lead them possibly themselves to defend the reasonings which they find being received as demonstrations by all persons of consideration, lest they appear not to understand them. And, finally, all others will easily yield to such a ma.s.s of evidence, and there will be none who dares to doubt the existence of G.o.d and the real and true distinction between the human soul and the body. It is for you now in your singular wisdom to judge of the importance of the establishment of such beliefs [you who see the disorders produced by the doubt of them]5 . But it would not become me to say more in consideration of the cause of G.o.d and religion to those who have always been the most worthy supports of the Catholic Church.

Preface to the Reader.

I have already slightly touched on these two questions of G.o.d and 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 that I had the design of treating these with any thoroughness, but only so to speak in pa.s.sing, and in order to ascertain by the judgment of the readers how I should treat them later on. For these questions have always appeared to me to be of such importance that I judged it suitable to speak of them more than once; and the road which I follow in the explanation of them is so little trodden, and so far removed from the ordinary path, that I did not judge it to be expedient to set it forth at length in French and in a Discourse which might be read by everyone, in case the feebler minds should believe that it was permitted to them to attempt to follow the same path.

But, having in this Discourse on Method begged all those who have found in my writings somewhat deserving of censure to do me the favour of acquainting me with the grounds of it, nothing worthy of remark has been objected to in them beyond two matters: to these two I wish here to reply in a few words before undertaking their more detailed discussion.

The first objection is that it does not follow from the fact that the human mind reflecting on itself does not perceive itself to be other than a thing that thinks, that its nature or its essence consists only in its being a thing that thinks, in the sense that this word only excludes all other things which might also be supposed to pertain to the nature of the soul. To this objection I reply that it was not my intention in that place to exclude these in accordance with the order that looks to the truth of the matter (as to which I was not then dealing), but only in accordance with the order of my thought [perception]; thus my meaning was that so far as I was aware, I knew nothing clearly as belonging to my essence, excepting that I was a thing that thinks, or a thing that has in itself the faculty of thinking. But I shall show hereafter how from the fact that I know no other thing which pertains to my essence, it follows that there is no other thing which really does belong to it.

The second objection is that it does not follow from the fact that I have in myself the idea of something more perfect than I am, that this idea is more perfect than I, and much less that what is represented by this idea exists. But I reply that in this term idea there is here something equivocal, for it may either be taken materially, as an act of my understanding, and in this sense it cannot be said that it is more perfect than I; or it may be taken objectively, as the thing which is represented by this act, which, although we do not suppose it to exist outside of my understanding, may, none the less, be more perfect than I, because of its essence. And in following out this Treatise I shall show more fully how, from the sole fact that I have in myself the idea of a thing more perfect than myself, it follows that this thing truly exists.

In addition to these two objections I have also seen two fairly lengthy works on this subject, which, however, did not so much impugn my reasonings as my conclusions, and this by arguments drawn from the ordinary atheistic sources. But, because such arguments cannot make any impression on the minds of those who really understand my reasonings, and as the judgments of many are so feeble and irrational that they very often allow themselves to be persuaded by the opinions which they have first formed, however false and far removed from reason they may be, rather than by a true and solid but subsequently received refutation of these opinions, I do not desire to reply here to their criticisms in case of being first of all obliged to state them. I shall only say in general that all that is said by the atheist against the existence of G.o.d, always depends either on the fact that we ascribe to G.o.d affections which are human, or that we attribute so much strength and wisdom to our minds that we even have the presumption to desire to determine and understand that which G.o.d can and ought to do. In this way all that they allege will cause us no difficulty, provided only we remember that we must consider our minds as things which are finite and limited, and G.o.d as a Being who is incomprehensible and infinite.

Now that I have once for all recognised and acknowledged the opinions of men, I at once begin to treat of G.o.d and the Human soul, and at the same time to treat of the whole of the First Philosophy, without however expecting any praise from the vulgar and without the hope that my book will have many readers. On the contrary, I should never advise anyone to read it excepting those who desire to meditate seriously with me, and who can detach their minds from affairs of sense, and deliver themselves entirely from every sort of prejudice. I know too well that such men exist in a very small number. But for those who, without caring to comprehend the order and connections of my reasonings, form their criticisms on detached portions arbitrarily selected, as is the custom with many, these, I say, will not obtain much profit from reading this Treatise. And although they perhaps in several parts find occasion of cavilling, they can for all their pains make no objection which is urgent or deserving of reply.

And inasmuch as I make no promise to others to satisfy them at once, and as I do not presume so much on my own powers as to believe myself capable of foreseeing all that can cause difficulty to anyone, I shall first of all set forth in these Meditations the very considerations by which I persuade myself that I have reached a certain and evident knowledge of the truth, in order to see if, by the same reasons which persuaded me, I can also persuade others. And, after that, I shall reply to the objections which have been made to me by persons of genius and learning to whom I have sent my Meditations for examination, before submitting them to the press. For they have made so many objections and these so different, that I venture to promise that it will be difficult for anyone to bring to mind criticisms of any consequence which have not been already touched upon. This is why I beg those who read these Meditations to form no judgment upon them unless they have given themselves the trouble to read all the objections as well as the replies which I have made to them.6

Synopsis of the Six Following Meditations.

In the first Meditation I set forth the reasons for which we may, generally speaking, doubt about all things and especially about material things, at least so long as we have no other foundations for the sciences than those which we have hitherto possessed. But although the utility of a Doubt which is so general does not at first appear, it is at the same time very great, inasmuch as it delivers us from every kind of prejudice, and sets out for us a very simple way by which the mind may detach itself from the senses; and finally it makes it impossible for us ever to doubt those things which we have once discovered to be true.

In the second Meditation, mind, which making use of the liberty which pertains to it, takes for granted that all those things of whose existence it has the least doubt, are non- existent, recognises that it is however absolutely impossible that it does not itself exist. This point is likewise of the greatest moment, inasmuch as by this means a distinction is easily drawn between the things which pertain to mindthat is to say to the intellectual natureand those which pertain to body.

But because it may be that some expect from me in this place a statement of the reasons establishing the immortality of the soul, I feel that I should here make known to them that having aimed at writing nothing in all this Treatise of which I do not possess very exact demonstrations, I am obliged to follow a similar order to that made use of by the geometers, which is to begin by putting forward as premises all those things upon which the proposition that we seek depends, before coming to any conclusion regarding it. Now the first and princ.i.p.al matter which is requisite for thoroughly understanding the immortality of the soul is to form the clearest possible conception of it, and one which will be entirely distinct from all the conceptions which we may have of body; and in this Meditation this has been done. In addition to this it is requisite that we may be a.s.sured that all the things which we conceive clearly and distinctly are true in the very way in which we think them; and this could not be proved previously to the Fourth Mediation. Further we must have a distinct conception of corporeal nature, which is given partly in this Second, and partly in the Fifth and Sixth Meditations. And finally we should conclude from all this, that those things which we conceive clearly and distinctly as being diverse substances, as we regard mind and body to be, are really substances essentially distinct one from the other; and this is the conclusion of the Sixth Meditation. This is further confirmed in this same Meditation by the fact that we cannot conceive of body excepting in so far as it is divisible, while the mind cannot be conceived of excepting as indivisible. For we are not able to conceive of the half of a mind as we can do of the smallest of all bodies; so that we see that not only are their natures different but even in some respects contrary to one another. I have not however dealt further with this matter in this treatise, both because what I have said is sufficient to show clearly enough that the extinction of the mind does not follow from the corruption of the body, and also to give men the hope of another life after death, as also because the premises from which the immortality of the soul may be deduced depend on an elucidation of a complete system of Physics. This would mean to establish in the first place that all substances generallythat is to say all things which cannot exist without being created by G.o.dare in their nature incorruptible, and that they can never cease to exist unless G.o.d, in denying to them his concurrence, reduce them to nought; and secondly that body, regarded generally, is a substance, which is the reason why it also cannot perish, but that the human body, inasmuch as it differs from other bodies, is composed only of a certain configuration of members and of other similar accidents, while the human mind is not similarly composed of any accidents, but is a pure substance. For although all the accidents of mind be changed, although, for instance, it think certain things, will others, perceive others, etc., despite all this it does not emerge from these changes another mind: the human body on the other hand becomes a different thing from the sole fact that the figure or form of any of its portions is found to be changed.

From this it follows that the human body may indeed easily enough perish, but the mind [or soul of man (I make no distinction between them)] is owing to its nature immortal.

In the third Meditation it seems to me that I have explained at sufficient length the princ.i.p.al argument of which I make use in order to prove the existence of G.o.d. But none the less, because I did not wish in that place to make use of any comparisons derived from corporeal things, so as to withdraw as much as I could the minds of readers from the senses, there may perhaps have remained many obscurities which, however, will, I hope, be entirely removed by the Replies which I have made to the Objections which have been set before me. Amongst others there is, for example, this one, "How the idea in us of a being supremely perfect possesses so much objective reality [that is to say partic.i.p.ates by representation in so many degrees of being and perfection] that it necessarily proceeds from a cause which is absolutely perfect." This is ill.u.s.trated in these Replies by the comparison of a very perfect machine, the idea of which is found in the mind of some workman. For as the objective contrivance of this idea must have some cause, i.e. either the science of the workman or that of some other from whom he has received the idea, it is similarly impossible that the idea of G.o.d which is in us should not have G.o.d himself as its cause.

In the fourth Meditation it is shown that all these things which we very clearly and distinctly perceive are true, and at the same time it is explained in what the nature of error or falsity consists. This must of necessity be known both for the confirmation of the preceding truths and for the better comprehension of those that follow. (But it must meanwhile be remarked that I do not in any way there treat of sinthat is to say of the error which is committed in the pursuit of good and evil, but only of that which arises in the deciding between the true and the false. And I do not intend to speak of matters pertaining to the Faith or the conduct of life, but only of those which concern speculative truths, and which may be known by the sole aid of the light of nature.)

In the fifth Meditation corporeal nature generally is explained, and in addition to this the existence of G.o.d is demonstrated by a new proof in which there may possibly be certain difficulties also, but the solution of these will be seen in the Replies to the Objections. And further I show in what sense it is true to say that the certainty of geometrical demonstrations is itself dependent on the knowledge of G.o.d.

Finally in the Sixth I distinguish the action of the understanding7 from that of the imagination;8 the marks by which this distinction is made are described. I here show that the mind of man is really distinct from the body, and at the same time that the two are so closely joined together that they form, so to speak, a single thing. All the errors which proceed from the senses are then surveyed, while the means of avoiding them are demonstrated, and finally all the reasons from which we may deduce the existence of material things are set forth. Not that I judge them to be very useful in establishing that which they prove, to wit, that there is in truth a world, that men possess bodies, and other such things which never have been doubted by anyone of sense; but because in considering these closely we come to see that they are neither so strong nor so evident as those arguments which lead us to the knowledge of our mind and of G.o.d; so that these last must be the most certain and most evident facts which can fall within the cognizance of the human mind. And this is the whole matter that I have tried to prove in these Meditations, for which reason I here omit to speak of many other questions which I dealt incidentally in this discussion.

MEDITATIONS ON THE FIRST PHILOSOPHY IN WHICH THE EXISTENCE OF G.o.d AND THE DISTINCTION BETWEEN MIND AND BODY ARE DEMONSTRATED.

Meditation I.

Of the things which may be brought within the sphere of the doubtful.

It is now some years since I detected how many were the false beliefs that I had from my earliest youth admitted as true, and how doubtful was everything I had since constructed on this basis; and from that time I was convinced that I must once for all seriously undertake to rid myself of all the opinions which I had formerly accepted, and commence to build anew from the foundation, if I wanted to establish any firm and permanent structure in the sciences. But as this enterprise appeared to be a very great one, I waited until I had attained an age so mature that I could not hope that at any later date I should be better fitted to execute my design.

This reason caused me to delay so long that I should feel that I was doing wrong were I to occupy in deliberation the time that yet remains to me for action. To-day, then, since very opportunely for the plan I have in view I have delivered my mind from every care [and am happily agitated by no pa.s.sions]

and since I have procured for myself an a.s.sured leisure in a peaceable retirement, I shall at last seriously and freely address myself to the general upheaval of all my former opinions.

Now for this object it is not necessary that I should show that all of these are falseI shall perhaps never arrive at this end. But inasmuch as reason already persuades me that I ought no less carefully to withhold my a.s.sent from matters which are not entirely certain and indubitable than from those which appear to me manifestly to be false, if I am able to find in each one some reason to doubt, this will suffice to justify my rejecting the whole. And for that end it will not be requisite that I should examine each in particular, which would be an endless undertaking; for owing to the fact that the destruction of the foundations of necessity brings with it the downfall of the rest of the edifice, I shall only in the first place attack those principles upon which all my former opinions rested.

All that up to the present time I have accepted as most true and certain I have learned either from the senses or through the senses; but it is sometimes proved to me that these senses are deceptive, and it is wiser not to trust entirely to anything by which we have once been deceived.

But it may be that although the senses sometimes deceive us concerning things which are hardly perceptible, or very far away, there are yet many others to be met with as to which we cannot reasonably have any doubt, although we recognise them by their means. For example, there is the fact that I am here, seated by the fire, attired in a dressing gown, having this paper in my hands and other similar matters. And how could I deny that these hands and this body are mine, were it not perhaps that I compare myself to certain persons, devoid of sense, whose cerebella are so troubled and clouded by the violent vapours of black bile, that they constantly a.s.sure us that they think they are kings when they are really quite poor, or that they are clothed in purple when they are really without covering, or who imagine that they have an earthenware head or are nothing but pumpkins or are made of gla.s.s. But they are mad, and I should not be any the less insane were I to follow examples so extravagant.

At the same time I must remember that I am a man, and that consequently I am in the habit of sleeping, and in my dreams representing to myself the same things or sometimes even less probable things, than do those who are insane in their waking moments. How often has it happened to me that in the night I dreamt that I found myself in this particular place, that I was dressed and seated near the fire, whilst in reality I was lying undressed in bed! At this moment it does indeed seem to me that it is with eyes awake that I am looking at this paper; that this head which I move is not asleep, that it is deliberately and of set purpose that I extend my hand and perceive it; what happens in sleep does not appear so clear nor so distinct as does all this. But in thinking over this I remind myself that on many occasions I have in sleep been deceived by similar illusions, and in dwelling carefully on this reflection I see so manifestly that there are no certain indications by which we may clearly distinguish wakefulness from sleep that I am lost in astonishment. And my astonishment is such that it is almost capable of persuading me that I now dream.

Now let us a.s.sume that we are asleep and that all these particulars, e.g. that we open our eyes, shake our head, extend our hands, and so on, are but false delusions; and let us reflect that possibly neither our hands nor our whole body are such as they appear to us to be. At the same time we must at least confess that the things which are represented to us in sleep are like painted representations which can only have been formed as the counterparts of something real and true, and that in this way those general things at least, i.e. eyes, a head, hands, and a whole body, are not imaginary things, but things really existent. For, as a matter of fact, painters, even when they study with the greatest skill to represent sirens and satyrs by forms the most strange and extraordinary, cannot give them natures which are entirely new, but merely make a certain medley of the members of different animals; or if their imagination is extravagant enough to invent something so novel that nothing similar has ever before been seen, and that then their work represents a thing purely fict.i.tious and absolutely false, it is certain all the same that the colours of which this is composed are necessarily real. And for the same reason, although these general things, to with, [a body], eyes, a head, hands, and such like, may be imaginary, we are bound at the same time to confess that there are at least some other objects yet more simple and more universal, which are real and true; and of these just in the same way as with certain real colours, all these images of things which dwell in our thoughts, whether true and real or false and fantastic, are formed.

To such a cla.s.s of things pertains corporeal nature in general, and its extension, the figure of extended things, their quant.i.ty or magnitude and number, as also the place in which they are, the time which measures their duration, and so on.

That is possibly why our reasoning is not unjust when we conclude from this that Physics, Astronomy, Medicine and all other sciences which have as their end the consideration of composite things, are very dubious and uncertain; but that Arithmetic, Geometry and other sciences of that kind which only treat of things that are very simple and very general, without taking great trouble to ascertain whether they are actually existent or not, contain some measure of certainty and an element of the indubitable. For whether I am awake or asleep, two and three together always form five, and the square can never have more than four sides, and it does not seem possible that truths so clear and apparent can be suspected of any falsity [or uncertainty].

Nevertheless I have long had fixed in my mind the belief that an all-powerful G.o.d existed by whom I have been created such as I am. But how do I know that He has not brought it to pa.s.s that there is no earth, no heaven, no extended body, no magnitude, no place, and that nevertheless [I possess the perceptions of all these things and that] they seem to me to exist just exactly as I now see them? And, besides, as I sometimes imagine that others deceive themselves in the things which they think they know best, how do I know that I am not deceived every time that I add two and three, or count the sides of a square, or judge of things yet simpler, if anything simpler can be imagined? But possibly G.o.d has not desired that I should be thus deceived, for He is said to be supremely good. If, however, it is contrary to His goodness to have made me such that I constantly deceive myself, it would also appear to be contrary to His goodness to permit me to be sometimes deceived, and nevertheless I cannot doubt that He does permit this.

There may indeed be those who would prefer to deny the existence of a G.o.d so powerful, rather than believe that all other things are uncertain. But let us not oppose them for the present, and grant that all that is here said of a G.o.d is a fable; nevertheless in whatever way they suppose that I have arrived at the state of being that I have reachedwhether they attribute it to fate or to accident, or make out that it is by a continual succession of antecedents, or by some other methodsince to err and deceive oneself is a defect, it is clear that the greater will be the probability of my being so imperfect as to deceive myself ever, as is the Author to whom they a.s.sign my origin the less powerful. To these reasons I have certainly nothing to reply, but at the end I feel constrained to confess that there is nothing in all that I formerly believed to be true, of which I cannot in some measure doubt, and that not merely through want of thought or through levity, but for reasons which are very powerful and maturely considered; so that henceforth I ought not the less carefully to refrain from giving credence to these opinions than to that which is manifestly false, if I desire to arrive at any certainty [in the sciences].

But it is not sufficient to have made these remarks, we must also be careful to keep them in mind. For these ancient and commonly held opinions still revert frequently to my mind, long and familiar custom having given them the right to occupy my mind against my inclination and rendered them almost masters of my belief; nor will I ever lose the habit of deferring to them or of placing my confidence in them, so long as I consider them as they really are, i.e. opinions in some measure doubtful, as I have just shown, and at the same time highly probable, so that there is much more reason to believe in than to deny them. That is why I consider that I shall not be acting amiss, if, taking of set purpose a contrary belief, I allow myself to be deceived, and for a certain time pretend that all these opinions are entirely false and imaginary, until at last, having thus balanced my former prejudices with my latter [so that they cannot divert my opinions more to one side than to the other], my judgment will no longer be dominated by bad usage or turned away from the right knowledge of the truth. For I am a.s.sured that there can be neither peril nor error in this course, and that I cannot at present yield too much to distrust, since I am not considering the question of action, but only of knowledge.

I shall then suppose, not that G.o.d who is supremely good and the fountain of truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me; I shall consider that the heavens, the earth, colours, figures, sound, and all other external things are nought but the illusions and dreams of which this genius has availed himself in order to lay traps for my credulity; I shall consider myself as having no hands, no eyes, no flesh, no blood, nor any senses, yet falsely believing myself to possess all these things; I shall remain obstinately attached to this idea, and if by this means it is not in my power to arrive at the knowledge of any truth, I may at least do what is in my power [i.e. suspend my judgment], and with firm purpose avoid giving credence to any false thing, or being imposed upon by this arch deceiver, however powerful and deceptive he may be. But this task is a laborious one, and insensibly a certain la.s.situde leads me into the course of my ordinary life. And just as a captive who in sleep enjoys an imaginary liberty, when he begins to suspect that his liberty is but a dream, fears to awaken, and conspires with these agreeable illusions that the deception may be prolonged, so insensibly of my own accord I fall back into my former opinions, and I dread awakening from this slumber, lest the laborious wakefulness which would follow the tranquillity of this repose should have to be spent not in daylight, but in the excessive darkness of the difficulties which have just been discussed.

Meditation II

Of the Nature of the Human Mind; and that it is more easily known than the Body.

The Meditation of yesterday filled my mind with so many doubts that it is no longer in my power to forget them. And yet I do not see in what manner I can resolve them; and, just as if I had all of a sudden fallen into very deep water, I am so disconcerted that I can neither make certain of setting my feet on the bottom, nor can I swim and so support myself on the surface. I shall nevertheless make an effort and follow anew the same path as that on which I yesterday entered, i.e.

I shall proceed by setting aside all that in which the least doubt could be supposed to exist, just as if I had discovered that it was absolutely false; and I shall ever follow in this road until I have met with something which is certain, or at least, if I can do nothing else, until I have learned for certain that there is nothing in the world that is certain.

Archimedes, in order that he might draw the terrestrial globe out of its place, and transport it elsewhere, demanded only that one point should be fixed and immoveable; in the same way I shall have the right to conceive high hopes if I am happy enough to discover one thing only which is certain and indubitable.