René Descartes
Translated by
DONALD A.
CRESS
HACKETT PUBLISHING COMPANY
If this discourse seems too long to be read at one sitting, one might split it into six parts. In the first, one will find various discussions concerning the sciences. In the second part, the chief rules of the method which the author has been seeking. In the third part, some of the rules of morality which the author has derived from this method. In the fourth part, the reasons by which the author proves the existence of God and of the human soul, which are the foundations of his metaphysics. In the fifth part, the order of the questions in physics which the author has sought — and particularly the explanation of the heart's movement and other difficulties which pertain to medicine, as well as the difference between our soul and that of animals. And in the final part, what things the author believes are required to advance further in the study of nature than the author has done, and what reasons moved him to write.
Good sense is the most evenly distributed commodity in the world, for each of us considers himself to be so well endowed therewith that even those who are the most difficult to please in all other matters are not wont to desire more of it than they have. It is not likely that anyone is mistaken about this fact. Rather, it provides evidence that the power of judging rightly and of distinguishing the true from the false (which, properly speaking, is what people call good sense or reason) is naturally equal in all men. Thus the diversity of our opinions does not arise from the fact that some people are more reasonable than others, but simply from the fact that we conduct our thoughts along different lines and do not consider the same things. For it is not enough to have a good mind; the main thing is to use it well. The greatest souls are capable of the greatest vices as well as of the greatest virtues. And if they always follow the correct path, those who move forward only very slowly can make much greater progress than do those who run and stray from it.
For myself, I have never presumed that my mind was in any respect more perfect than anyone else's. In fact, I have often longed to have as quick a wit or as precise and distinct an imagination or as full and responsive a memory as certain other people. And I know of no other qualities that aid in the perfection of the mind. For as to reason or good sense, given that it alone makes us men and distinguishes us from animals, I prefer to believe that it exists whole and entire in each one of us. In this belief I am following the standard opinion held by philosophers who say that there are differences of degree only among accidents, but not among forms or natures of individuals of the same species.
But I shall have no fear of declaring that I think I have been fortunate; I have, since my youth, found myself on paths that have led me to certain considerations and maxims from which I have formed a method by means of which, it seems to me, I have the ways to increase my knowledge by degrees and to raise it gradually to the highest point to which the mediocrity of my mind and the short span of my life can allow it to attain. For I have already reaped from it such a harvest that, though as regards judgments I make of myself, I try always to lean toward caution, rather than toward presumption, and though, looking with a philosopher's eye at the various actions and enterprises of men, there is hardly one that does not seem to me vain and useless, I always take immense satisfaction in the progress that I think I have made in the search for truth; and I envisage such hopes for the future that if, among the occupations of men, as men, there is one which may be solidly good and important, I dare believe that it is the occupation I have chosen.
All the same, it could be that I am mistaken; and what I have taken for gold and diamonds may perhaps be nothing but copper and glass. I know how much we are prone to be mistaken in those things that deeply affect us, and also how judgments made by our friends must be held suspect when these judgments are in our favor. But I would be very happy to show in this discourse the paths that I have followed and to present my life as if in a picture, so that each person may judge it; learning what people commonly think about it may be a new means of teaching myself, which I shall add to those that I am accustomed to employing.
Thus my purpose here is not to teach the method that everyone ought to follow in order to conduct his reason correctly, but merely to show how I have tried to conduct mine. Those who take it upon themselves to give precepts ought to regard themselves as more competent than those to whom they give them; and if they are found wanting in the least detail, they are blameworthy. But, putting forward this essay as merely a history — or, if you prefer, a fable — in which, among the examples one can imitate, one also finds perhaps several others which one is right in not following, I hope that the essay will be useful to some, while harmful to none, and that my openness will be to everyone's liking.
I have been raised on letters from my childhood, and because I was convinced that through them one might acquire a clear and steady knowledge of everything that is useful for life, I possessed a tremendous desire to learn them. But, as soon as I completed this entire course of study, at the end of which one is ordinarily received into the ranks of the learned, I changed my mind entirely. For I was embarrassed by so many doubts and errors, which appeared in no way to profit me in my attempt at learning, except that more and more I discovered my ignorance. And nevertheless, I was in one of the most celebrated schools of Europe, where I thought there ought to be learned men — if in fact there were any such men in the world. I learned everything the others learned; and, not judging the disciplines taught there to be enough, I even went through every book I could lay my hands on that treated those disciplines considered the most curious and unusual. Moreover, I knew what judgments others were making about me; and it was apparent to me that I was rated no less than my peers, even though there already were those among them who were destined to succeed our teachers. And finally our century seems to me just as flourishing and as fertile in good minds as any of the preceding ones. All of this caused me to feel free to judge everybody else by myself, and to think that there has been no body of knowledge in the world which was of the sort that I had previously hoped to find.
Yet I never ceased admiring the academic exercises with which we occupied ourselves in school. I realized that the languages one learns there are necessary for the understanding of classical texts; that the gracefulness of fables awakens the mind; that memorable deeds recounted in histories uplift it, and, if read with discretion, aid in forming one's judgment; that reading good books is like a conversation with the noblest people of past centuries — their authors — indeed, even a studied conversation in which they uncover only the best of their thoughts; that eloquence has incomparable power and beauty; that poetry has a ravishing delicacy and sweetness; that mathematics contains very subtle inventions that can serve as much to satisfy the curious as to facilitate the arts and to diminish men's labour; that writings dealing with morals contain many lessons and exhortations to virtue that are quite useful; that theology teaches one how to go to heaven; that philosophy provides the means of speaking with probability about all things and of being held in admiration by the less learned; that law, medicine, and the other sciences bestow honors and riches upon those who cultivate them. And thus it is good to have examined all of these disciplines, even the most superstition-ridden and false of them, so that one might know their true worth and guard against being deceived.
But I thought that I had already given enough time to languages and also even to the reading of ancient books — to their histories and to their fables. For it is about the same to converse with those of other centuries as it is to travel. It is good to know something of the customs of various peoples, in order to judge our own more soundly and not to think that everything that is contrary to our way of doing things is worthy of scorn and against reason, as those who have seen nothing commonly think.
But when one takes too much time traveling, one becomes finally a stranger in one's own country; and when one is too curious about things that took place in past centuries, one ordinarily remains quite ignorant of what is taking place in one's own country. Moreover, fables make one imagine many events to be possible which really are impossible. And even the most accurate histories, if they neither alter nor augment the significance of things, in order to render them more worthy of being read, at least almost always omit the basest and least illustrious details, and thus the remainder does not appear as it really is, and those who govern their own conduct on the basis of the examples drawn from it are subject to falling into the extravagances of the knights of our novels and to conceiving plans that are beyond their powers.
I held eloquence in high regard and I loved poetry, but I believed that they were both gifts of the mind — not fruits of study. Those who possess the most forceful power of reasoning and who best order their thoughts so as to render them clear and intelligible can always best persuade one of what they are proposing, even if they speak only the dialect of Lower Brittany and have never learned rhetoric.1 [This dialect was considered rather barbarous and hardly suitable for sophisticated literary endeavors.] And those who are in possession of the most pleasing rhetorical devices and who know how to express them with the greatest of embellishment and sweetness will not fail to be the greatest poets, even if the art of poetry be unknown to them.
I took especially great pleasure in mathematics because of the certainty and the evidence of its arguments. But I did not yet notice its true usefulness and, thinking that it seemed useful only to the mechanical arts, I was astonished that, because its foundations were so solid and firm, no one had built anything more noble upon them. On the other hand, I compared the writings of the ancient pagans who discuss morals to very proud and magnificent palaces that are built on nothing but sand and mud. They place virtues on a high plateau and make them appear to be valued more than anything else in the world, but they do not sufficiently instruct us about how to know them; and often what they call by such a fine-sounding name is nothing more than insensibility, pride, despair, or parricide.
I revered our theology, and I desired as much as the next man to go to heaven; but having learned as something very certain that the road is no less open to the most ignorant than to the most learned, and that the revealed truths leading to it are beyond our understanding, I would not have dared to subject them to my feeble reasonings. And I believed that, in order to undertake the examination of these truths and to succeed in doing so, it was necessary to have some extraordinary assistance from heaven and to be more than a man.
Of philosophy I shall say only that, aware that philosophy has been cultivated over several centuries by the most excellent minds who have ever lived and that, nevertheless, there is nothing about which there is not some dispute — and thus nothing that is not doubtful — I was not so presumptuous as to hope to fare any better than the others; and that, considering how there can be various opinions that are held by learned people about the very same matter without there ever being any more than one opinion being true, I took to be virtually false everything that was merely probable.
As to the other sciences, since they derive their principles from philosophy, I judged that one could not have built anything solid upon foundations having so little firmness. And neither the honor nor the monetary gain they promised were sufficient to incite me to learn them, for I did not see myself, thank God, as being in a condition that forced me to make a trade out of knowledge for the enhancement of my fortune. And although I did not make a point of rejecting glory in the manner of the cynic, still I made light of that glory that was acquired only through false pretenses. And finally, as to the evil doctrines, I believed I already knew them for what they were worth, so as not to be subject to being deceived either by the promises of an alchemist, by the predictions of an astrologer, by the ruses of a magician, or by the artifices or boasting of anybody who makes a point of claiming to have more knowledge than he actually has.
That is why, as soon as age permitted me to escape the tutelage of my teachers. I left the study of letters completely. And resolving to search for no other knowledge than what I could find within myself, or in the great book of the world, I spent the rest of my youth traveling, seeing various courts and armies, frequenting peoples of varied humors and conditions, gathering varied experiences, testing myself in the encounters which fortune sent my way, and everywhere so reflecting upon what came my way that I could draw some profit from it. For it seemed to me that I could discover much more truth in the reasonings that each person makes concerning matters that are important to him, whose outcome ought to cost him dearly later on if he has judged incorrectly, than in those reasonings that a man of letters makes in his private room, which touch on speculations producing no effect, and which for him have no other consequence except perhaps that the more they are removed from common sense, he will derive all the more vanity from them, for he will have to employ that much more wit and artifice in attempting to make them probable. And I have always had an especially great craving for learning to distinguish the true from the false, to see my way clearly in my actions, and to go forward with confidence in this life.
It is true that, while I spent time merely observing the customs of other men, I found hardly anything about which to be confident and that I noticed there was about as much diversity as I had earlier found among the opinions of philosophers. Thus the greatest profit I derived from this was that on realizing that many things, although they seemed very extravagant and ridiculous to us, did not cease being commonly accepted and approved by other great peoples, I learned to believe nothing very firmly concerning what I had been persuaded to believe only by example and custom; and thus I gradually freed myself from many errors that can darken our natural light and render us less able to listen to reason. But after spending many years thus studying in the book of the world and in trying to gain experience, I made up my mind one day also to study myself and to spend all the powers of my mind in choosing the ways which I ought to follow. For me this procedure was much more successful, it seems, than if I had never left either my country or my books.
I was in Germany then, where the wars — which are still continuing there2[The Thirty Years War (1618-1648).] — called me; and while I was returning to the army from the coronation of the emperor, the onset of winter held me up in quarters where, finding no conversation with which to be diverted and, fortunately, otherwise having no worries or passions which troubled me, I remained for a whole day by myself in a small stove-heated room,3 [There is no need to allege that Descartes sat in or on a stove. A poele is simply a room heated by an earthenware stove. Cf. E. Gilson, Discours de la méthode: texte et commentaire (Paris: Vrin, 1976), p. 157.] where I had complete leisure for communing with my thoughts. Among them, one of the first that I thought of considering was that often there is less perfection in works made of several pieces and in works made by the hands of several masters than in those works on which but one master has worked. Thus one sees that buildings undertaken and completed by a single architect are commonly more beautiful and better ordered than those that several architects have tried to patch up, using old walls that had been built for other purposes. Thus these ancient cities that were once merely straggling villages and have become in the course of time great cities are commonly quite poorly laid out, compared to those well-ordered towns that an engineer lays out on a vacant plain as it suits his fancy. And although, upon considering one by one buildings in the former class of towns, one finds as much art or more than one finds in buildings of the latter class of towns, still, upon seeing how the buildings are arranged — here a large one, there a small one — and how they make the streets crooked and uneven, one will say that it is chance more than the will of some men using their reason that has arranged them thus. And if one considers that there have nevertheless always been officials responsible for seeing that private buildings be made to serve as an ornament for the public, one will know that it is difficult to produce a finely executed product by laboring only on the works of others. Thus I imagined that peoples who, having once been half savages and having been civilized only gradually, have made their laws only to the extent that the inconvenience caused by crimes and quarrels forced them to do so, would not be as well ordered as those who, from the very beginning of their coming together, have followed the fundamental precepts of some prudent legislator. Thus it is quite certain that the state of the true religion, whose ordinances were fixed by God alone, ought to be incomparably better governed than all the others. And, speaking of matters human, I believe that if Sparta flourished greatly in the past, it was not because of the goodness of each of its laws taken by itself, since some of them were very strange and even contrary to good morals, but because, having been invented by only one person, they all tended toward the same goal. And thus I thought that book learning, at least the kind whose arguments are merely probable and have no demonstrations — having been built up from and enlarged gradually by the opinions of many different people — does not draw as near to the truth as the simple reasonings that can be made naturally by a man of good sense concerning what he encounters. And thus again I thought that, given the fact that we were all children before being adults and that for a long time it was our lot to be governed by our appetites and our teachers (both were often in conflict with one another, and perhaps none of them consistently gave us the best advice), it is almost impossible for our judgments to be as pure or solid as they would have been had we the full use of our reason from the moment of our birth and had we never been led by anything but our reason.
It is true that one does not see people pulling down all the houses in a city simply to rebuild them some other way and to make the streets more attractive; but one does see that several people do tear down their own houses in order to rebuild them, and that even in some cases they are forced to do so when their houses are in danger of collapsing and the foundations are not very steadfast. Taking this example to heart, I was persuaded that it was not really likely that a single individual might plan to reform a state by changing everything from the very foundations and by toppling it in order to set it up again; nor even also to reform all of the sciences or the order established in the schools for teaching them; but, that I could not do better than to try once and for all to get all the beliefs I had accepted from birth out of my mind, so that once I have reconciled them with reason I might again set up either other, better ones or even the same ones. And I firmly believed that by this means I would succeed in conducting my life much better than were I to build only on old foundations or to lean only on the principles of which I permitted myself to be persuaded in my youth without ever having examined whether or not they were true. For although I noticed various difficulties in this operation, still they did not seem irremediable or comparable to those difficulties arising in the reformation of the least things which affect the public. These great bodies are too difficult to raise up once they have been knocked down or even to maintain once they have been shaken; and their falls can only be very violent. Now as to their imperfections, if they have any (and the mere fact of their diversity suffices to assure one that many of them are imperfect), usage has doubtlessly mitigated them and has even imperceptibly averted or corrected a great number of them, for which deliberate foresight could not have provided so well. And finally, these imperfections are almost always more tolerable than what it takes to change them; similarly, the great roads that wind around mountains become gradually so level and suitable by dint of being used frequently, that it is much better to follow these roads than to try to go by a more direct route, climbing over rocks and descending to the bottom of precipices.
This is why I could not approve of all of those trouble-making and quarrelsome types who, called neither by birth nor by fortune to manage public affairs, never cease in their imagination to effect some new reformation. And if I thought there were the slightest thing in this essay by means of which one might suspect me of such folly, I would be very sorry to permit its publication. My plan has never been more than to try to reform my own thoughts and to build upon a foundation which is completely my own. And if, my work having sufficiently pleased me, I show it to you here as a model, it is not for that reason that I wish to advise anyone to imitate it. Perhaps those with whom God has better shared his graces have more lofty plans; but I fear that this plan of mine may already be too arduous for many. The single resolution to detach oneself from all the beliefs one has once accepted as true is not an example that everyone ought to follow; and the world consists almost completely of but two kinds of people and for these two kinds it is not at all suitable: namely those who, believing themselves more capable than they really are, cannot help making premature judgments and do not have enough patience to conduct their thoughts in an orderly manner; thus, if they once take the liberty to doubt the principles they have accepted and to keep away from the common path, they could never keep to the path one must take in order to go in a more forward direction — they would remain lost all of their lives. Now as for those people who have enough reason or modesty to judge that they are less capable to distinguish the true from the false than are others by whom they can be instructed, they ought to content themselves more with following the opinions of these others than to look for better opinions on their own.
And for my part, I would unquestionably have been among these latter persons were I to have had only one master or had never seen the differences that have always existed among the opinions of the most learned people. But having learned since my school days that one cannot imagine anything so strange or unbelievable that it has not been said by some philosopher, and since then, during my travels, having acknowledged that those who have feelings quite contrary to our own are not for that reason barbarians or savages, but that many of them use their reason as much or more than we do, and having considered how the very same man with his very own mind, having been brought up from infancy among the French or the Germans becomes different from what he would be had he always lived among the Chinese or among cannibals; and how, even to the fashions of our clothing, the same thing that pleased us ten years ago and that perhaps might again please us ten years from now seem to us extravagant and ridiculous. Thus it is more custom and example that persuades us than certain knowledge, and for all that, the majority opinion is not a proof worth anything for truths that are a bit difficult to discover, since it is more likely that only one man has found them than a whole people: I could find no one whose opinions, it seemed to me, ought to be preferred over the others, and I found myself constrained to try to lead myself on my own.
But, like a man who walks alone and in the shadows, I resolved to go so slowly and to use so much circumspection in all things that, if I never advanced but slightly, I would at least avoid falling. Moreover, I did not wish to begin to reject utterly any of these opinions that could have at some time slipped into my head without having been placed there by my reason, until I had already spent sufficient time formulating the outline of the work I was attempting and searching for the true method of arriving at the knowledge of everything my mind was capable of attaining.
In my younger days I studied, among the parts of philosophy, a bit of logic, and in mathematics, some geometrical analysis and algebra — three arts or sciences that seemed destined to contribute something to my plan. But in examining them, I saw that, in the case of logic, its syllogisms and the greater part of its other lessons served more to explain to someone else what one knows, or even, like the art of Lully,4[Ramon Lull (ca. 1236-1315), Catalan philosopher and Franciscan who wrote in defense of Christianity against the Moors by attempting to demonstrate the articles of faith by means of logic. Descartes seems to have encountered a Lullist in Dordrecht who could hold forth on any subject whatever for long periods of time. This encounter, more than any direct contact with the writings of Lull, seems to have colored Descartes' understanding of the "art of Lully" Cf. E. Gilson, Discours de la méthode: texte et commentaire, pp. 185-186.] to speak without judgment concerning matters about which one is ignorant, than to learn them. And although it contains, in effect, very true and good
precepts, nevertheless there are so many others, mixed up with them, that are either harmful or superfluous, that it is almost as hard to separate the latter precepts from the former as it is to draw a Diana or a Minerva from a block of marble that is not yet blocked out. Now, as to the analysis of the ancients and the algebra of the moderns, apart from the fact that they apply only to very abstract matters and seem to have no practical utility, the former is always so subject to the consideration of figures that it cannot exercise the understanding without exhausting the imagination; and in the case of algebra, one is so governed by certain laws and symbols that out of it has been made a confused and obscure art that encumbers the mind instead of a science that cultivates it. That is why I believed it necessary to search for another method that, while embracing the advantages of the three, was free from their defects. And since the multiplicity of laws often provides excuses for vices, so that a state is much better when, having but a few laws, its laws are strictly observed; so, in place of the large number of rules of which logic is composed. I believed that the following four rules would be sufficient, provided I made a firm and constant resolution not even once to fail to observe them:
The first was never to accept anything as true that I did not know evidently to be so; that is, carefully to avoid precipitous judgment and prejudice; and to include nothing more in my judgments than what presented itself to my mind with such clarity and distinctness that I would have no occasion to put it in doubt.
The second, to divide each of the difficulties I was examining into as many parts as possible and as is required to solve them best.
The third, to conduct my thoughts in an orderly fashion, commencing with the simplest and easiest to know objects, to rise gradually, as by degrees, to the knowledge of the most composite things, and even supposing an order among those things that do not naturally precede one another.
And last, everywhere to make enumerations so complete and reviews so general that I would be sure of having omitted nothing.
Those long chains of reasoning, each of them simple and easy, that geometricians commonly use to attain their most difficult demonstrations, have given me an occasion for imagining that all the things that can fall within human knowledge follow one another in the same way and that, provided only that one abstain from accepting anything as true that is not true, and that one always maintains the order to be followed in deducing the one from the other, there is nothing so far distant that one cannot finally reach nor so hidden that one cannot discover. And I was not very worried about seeking which of them it would be necessary to
begin with; for I already knew that it was with the simplest and easiest to know. And considering that of all those who have already searched for truth in the sciences, only the mathematicians were able to find demonstrations, that is, certain and evident reasons, I did not doubt that it was with these same starting points that they had conducted their examinations; although I expected no further usefulness from them, except that they would accustom my mind to feed upon truths and not to be content with false reasons. But in all of this it was not my plan to try to learn all of the specific sciences that commonly are called mathematics; and seeing that, even though their objects differed, they did not cease to be in accord with one another, in that they consider only the various relations or proportions which are in these objects, I believed it would be more worthwhile were I to examine only these proportions in a general way, and to suppose them to be in concrete objects only to the extent that these objects aid me in making it easier to acquire knowledge of these proportions, and also without in any way binding these proportions to those objects, so that later one can apply them all the better to everything else to which they might pertain. Now, having noticed that, in order to know these proportions, I occasionally needed to consider each of them individually, and sometimes only to remember them, or to gather up several of them together, I believed that, to consider them better in particular, I ought to suppose them as relations between lines, since I found nothing more simple, nothing that I could more distinctly represent to my imagination and my senses; but to remember them or to grasp them all together, I would have had to explicate them by means of certain symbols, the shortest ones possible; and by this means I would borrow all of the better aspects of geometrical analysis and algebra, and I would correct all the defects of the one by means of the other.
In effect, I dare say that the exact observance of these few precepts that I have chosen gave me such a facility for disentangling all the problems to which these two sciences tended, that in the two or three months I spent examining them, having begun from the simplest and most general — and each truth that I found being a rule which I later used to find others — I not only succeeded in several problem areas that I had once judged very difficult, but it also seemed to me toward the end that I could determine, even in those problem areas where I was ignorant, by what means and how far it would be possible to resolve them. In this perhaps I shall not seem to you to be too vain, if you were to consider that, there being but one truth for each thing, anyone who finds it knows as much as one can know about that thing; and that, for example, a child given lessons in arithmetic, having made one addition in accordance with its rules, can be assured of having found everything the human mind can find bearing on the sum he has examined. For thus, the method, which teaches one to follow the true order and to enumerate exactly all the circumstances of what one is seeking, contains everything that gives certainty to the rules of arithmetic.
But what pleased me the most about this method was that by means of it I was assured of using my reason in everything, if not perfectly, then at least as best as I can. Moreover, I felt that in practicing this method my mind was gradually getting into the habit of conceiving its object more rigorously and more distinctly and that, not having subjected it to any particular matter, I promised myself to apply the method just as profitably to the problems of the other sciences, as I had done to problems in algebra. Not that, on account of this, I dared immediately to undertake an examination of whatever presented itself; for even that would have been contrary to the order prescribed by the method. But having noticed that their principles must all be borrowed from philosophy, in which I still found nothing certain, I thought that I ought, above all, to try to establish therein something certain; and I thought that, this being the most important thing in the world, where precipitous judgment and prejudice were most to be feared, I ought not to have tried to succeed at doing so until I had reached a much more mature age than merely twenty-three, which I was then; and I thought that I should previously spend much time preparing myself, as much in rooting out of my mind all the wrong opinions that I had accepted before that time as in accumulating many experiences — later to be the stuff of my reasonings — and in always exercising myself in the method I had prescribed for myself so as to be stronger and stronger in its use.
Now just as it is not enough, before beginning to rebuild the house where one lives, to pull it down, to make provisions for materials and architects, or to take a try at architecture for oneself, and also to have carefully worked out the floorplan; one must provide for something else in addition, namely where one can be conveniently sheltered while working on the other building; so too, in order not to remain irresolute in my actions while reason requires me to be so in my judgments, and in order not to cease living during that time as happily as possible, I formulated a provisional code of morals, which consisted of but three or four maxims, that I want to share with you.
The first was to obey the laws and the customs of my country, firmly holding on to the religion in which, by God's grace, I was instructed from childhood, and governing myself in all other things according to the most moderate opinions and those furthest from excess that were
commonly accepted in practice by the most sensible of those people with whom I would have to live. For, already beginning to count my own opinions as nothing, since I wished to remit all opinions to examination, I was assured that I could not do better than to follow the opinions of those who were the most sensible. And although there may perhaps be people among the Persians and the Chinese just as sensible as there are among ourselves, it seemed to me that the most useful course of action was to rule myself in accordance with those with whom I had to live, and that, to know their true opinions, I ought to observe what they do rather than what they say, not only because in the corruption of our morals there are few people who are willing to say all they believe, but also because many do not know what they believe; for, given that the action of thought by which one believes something is different from that by which one knows that one believes it, the one often occurs without the other. And among several opinions held equally, I would choose only the most moderate, not only because it is always the most suitable for action and probably the best (every excess usually being bad), but also so as to stray less, in case I am mistaken, from the true road — having chosen one of the two extremes — when it was the other one I should have followed. And in particular I placed among the excesses all of the promises by which one curtails something of one's freedom. Not that I disapprove of laws that, to remedy the inconstancy of weak minds, permit (when one has a good plan or even, for the security of commerce, a plan that is only indifferent) one to make vows or contracts that oblige one to persevere in them; but because I have seen nothing in the world that remains always in the same state and because, for my part, I promised to perfect my judgments more and more, and not to render them worse, I would have believed I committed a grave indiscretion against good sense if, having once approved of something, I obligated myself to take it to be good at a later time when perhaps it would have ceased to be so or when I would have ceased judging it to be good.
My second maxim was to be as firm and resolute in my actions as I could be, and to follow with no less constancy the most doubtful opinions, once I have decided on them, than if they were very certain. In this I would imitate travelers who, finding themselves lost in a forest, ought not wander this way and that, or, what is worse, remain in one place, but ought always walk as straight a line as they can in one direction and not change course for feeble reasons, even if at the outset it was perhaps only chance that made them choose it; for by this means, if they are not going where they wish, they will finally arrive at least somewhere where they probably will be better off than in the middle of a forest. And thus the actions of life often tolerating no delay, it is a very certain truth that, when it is not in our power to discern the truest opinions, we ought to follow the most probable; and even if we observe no more probability in some than in others, nevertheless we ought to fix ourselves on some of them and later consider them no longer as doubtful, insofar as they relate to practical affairs, but as very true and very certain, since reason, which has caused us to make this determination, is itself of the same sort. And this insight was capable, from that point onward, of freeing me from the repentence and remorse that commonly agitate the consciences of these frail and irresolute minds that allow themselves to go about with inconstancy, treating things as if they were good, only to judge them later to be bad.
My third maxim was always to try to conquer myself rather than fortune, to change my desires rather than the order of the world; and generally to become accustomed to believing that there is nothing that is utterly within our power, except for our thoughts, so that, after having done our best regarding things external to us, everything that fails to bring us success, from our point of view, is absolutely impossible. And this principle alone seemed sufficient to stop me from desiring anything in the future that I would not acquire, and thus seemed sufficient to make me contented. For, our will tending naturally to desire only what our intellect represents to it as in some way possible, it is certain that, if we consider all of the goods that are outside us as equally beyond our power, we should have no more regrets about lacking what seems owed to us at birth, when we are deprived of them through no fault of our own, than we should have for not possessing the kingdoms of China or Mexico. Thus, making a virtue of necessity, as they say, we shall no more desire to be healthy if we are sick, or to be free if we are in prison, than we would desire to have a body made of matter as incorruptible as diamonds, or wings with which to fly like birds. But I confess that long exercise is needed as well as frequently repeated meditation in order to become accustomed to looking at everything from this point of view; and I believe that in this principally lay the secret of the philosophers who at one time were able to free themselves from fortune's domination and who could, despite their sorrows and their poverty, rival their gods in their happiness. For occupying themselves ceaselessly with considering the limits prescribed to them by nature, they so perfectly persuaded themselves that nothing was in their power save their own thoughts, that this alone was sufficient to stop them from having feelings about any other objects; and they controlled their thoughts so absolutely, that they thereby had some reason for judging themselves richer, more powerful, freer, and happier than those other men who, not having this philosophy — however favored by nature and fortune as they may be — never controlled everything they wished to control.
Finally, to conclude this code of morals, I thought it advisable to review the various occupations that men take up in this life, so as to try to choose the best one; and, not wanting to say anything about the occupations of others, I believed I could not do better than to continue in the occupation I was in at that time, namely cultivating my reason all my life and advancing, as best as I could, in the knowledge of truth, following the method I had prescribed to myself. I had met with such intense satisfaction, since the time I had begun to make use of this method, that I did not believe one could receive sweeter or more innocent satisfaction in this life; and, discovering every day by its means some truths that seemed important to me and commonly ignored by other men, I had a satisfaction that so filled my mind that nothing else was of any consequence to me. In addition, the three preceding maxims were founded merely on the plan I had of continuing my self-instruction; for since God has given each of us a certain light by which to distinguish the true from the false, I should not believe I ought to be content for a single moment with the opinions of others, had I not proposed to use my own judgment to examine them when there was time; and I should not have been able to be free of scruple in following these opinions, had I not hoped I would not waste the opportunity thereby of finding better ones, in case there were better ones. And finally, I could not have curbed my desires or have been contented, had I not followed a road by which, believing I was assured of acquiring all the knowledge of which I was capable, I believed I was assured of acquiring by the same means all the true goods that would ever be in my power; given that our will neither pursues nor flees an object unless our intellect represents that object to the will as either good or bad, it suffices to judge well in order to do well, and to judge as best one can, in order also to do one's best, that is, to acquire all the virtues and, along with them, all the other goods that one can acquire; and while one is certain that this is the case, one could not fail to be contented.
After having assured myself of these maxims and having put them aside, along with the truths of the faith, which have always held first place in my set of beliefs, I judged that, as far as the rest of my opinions were concerned, I could freely undertake to rid myself of them. And insofar as I hoped I could be more successful in social interchange than in remaining any longer shut up in the small stove-heated room where I had had all of these thoughts, I set out again on my travels, the winter not yet completely over. And in all the following nine years I did nothing but wander here and there about the world, trying to be more a spectator than an actor in all the comedies that were being played out there; and reflecting particularly in each matter on what might render it suspect and give us occasion for error, I meanwhile rooted out from my mind all the errors that had been able to creep in undetected. Not that I was thereby aping the sceptics who doubt merely for the sake of doubting and put on the affectation of perpetual indecision; for, on the contrary, my entire plan tended simply to give me assurance and to reject shifting ground and sand so as to find rock or clay. In this I was quite successful, it seems to me, inasmuch as, trying to discover the falsity or uncertainty of the propositions I was examining — not by feeble conjectures but by clear and certain reasonings — I never found anything that was so doubtful that I could not draw some rather certain conclusion from it, even if it were merely that it contained nothing certain. And just as in tearing down an old house, one usually saves the wreckage for use in building the new house, similarly, in destroying all of those opinions that I judged to be poorly supported, I made various observations and acquired many experiences that I later found useful in establishing opinions that were more certain. Moreover, I continued to practice the method I had prescribed for myself; for besides taking care generally to conduct all my thoughts according to the rules of this method, from time to time I set aside a few hours that I spent in practicing the method on mathematical problems, or even in various other problems that I could render similar to those of mathematics, by detaching them from all the principles of the other sciences, which I did not find to be sufficiently firm, as you will observe I have done in several cases that are explained in this volume. And thus, without living any other way in outward appearance than those who, having no other task but living sweet and innocent lives, are eager to separate pleasures from vices and who, to enjoy their leisure without becoming bored, engage in all sorts of honorable diversions, I did not cease to pursue my plan and to profit in the knowledge of the truth, perhaps more than if I had done nothing but read books or keep company with men of letters.
All the same, these nine years slipped away before I had as yet taken any stand regarding the difficulties commonly debated by learned men, or had begun to seek the foundations of any philosophy that was more certain than the commonly accepted one. And the example of many excellent minds, which, having already had this plan, appeared to me not to have succeeded, made me conjure thoughts of so many difficulties that perhaps I should not yet have dared to try it if I had not seen that some people had already passed the rumor around that I had already succeeded. I cannot say on what they based this opinion; and if I have contributed anything to this by my conversations, it must have been more because I admitted what I did not know more ingenuously than do those who have studied only a little, and perhaps also because I showed the reasons I had for doubting many of the things that other people regard as certain, than because I was boasting of any knowledge. But being decent enough not to want someone to take me for something other than I was. I thought it necessary to try by every means to make myself worthy of the reputation bestowed upon me; and it is exactly eight years since this desire made me resolve to take my leave of all those places where I could have acquaintances, and to retire here, in a country where the long duration of the war has established such well-ordered discipline that the armies quartered there seem to be there solely for the purpose of guaranteeing the enjoyment of the fruits of peace with even greater security, and where among the crowds of a great and very busy people and more concerned with their own affairs than curious about the affairs of others, I have been able to live as solitary and as retired a life as I could in the remotest deserts — but without lacking any of the amenities that are to be found in the most populous cities.
I do not know whether I ought to tell you about the first meditations I made there; for they are so metaphysical and so out of the ordinary, that perhaps they would not be to everyone's liking. Nevertheless, so that one might be able to judge whether the foundations I have laid are sufficiently firm, I am in some sense forced to speak. For a long time I have noticed that in moral matters one must sometimes follow opinions that one knows are quite uncertain, just as if they were indubitable, as has been said above; but since then I desired to attend only to the search for truth, I thought it necessary that I do exactly the opposite, and that I reject as absolutely false everything in which I could imagine the least doubt, so as to see whether, after this process, anything in my set of beliefs remains that is entirely indubitable. Thus, since our senses sometimes deceive us, I decided to suppose that nothing was exactly as our senses would have us imagine. And since there are men who err in reasoning, even in the simplest matters in geometry, and commit paralogisms, judging that I was just as prone to err as the next man, I rejected as false all the reasonings that I had previously taken for demonstrations. And finally, taking into account the fact that the same thoughts we have when we are awake can also come to us when we are asleep, without any of the latter thoughts being true, I resolved to pretend that everything that had ever entered my mind was no more true than the illusions of my dreams. But immediately afterward I noticed that, during the time I wanted thus to think that everything was false, it was necessary that I, who thought thus, be something. And noticing that this truth — I think, therefore I am — was so firm and so certain that the most extravagant suppositions of the sceptics were unable to shake it, I judged that I could accept it without scruple as the first principle of the philosophy I was seeking.
Then, examining with attention what I was, I saw that I could pretend that I had no body and that there was no world nor any place where I was, but that I could not pretend, on that account, that I did not exist; and that, on the contrary, from the very fact that I thought about doubting the truth of other things, it followed very evidently and very certainly that I existed. On the other hand, had I simply stopped thinking, even if all the rest of what I have ever imagined were true, I would have no reason to believe that I existed. From this I knew that I was a substance the whole essence or nature of which was merely to think, and which, in order to exist, needed no place and depended on no material thing. Thus this "I," that is, the soul through which I am what I am, is entirely distinct from the body, and is even easier to know than the body, and even if there were no body, the soul would not cease to be all that it is.
After this, I considered in a general way what is needed for a proposition to be true and certain; for since I had just found a proposition that I knew was true, I thought I ought also know in what this certitude consists. And having noticed that there is nothing in all of this — I think, therefore I am — that assures me that I am uttering the truth, except that I see very clearly that, in order to think, one must exist; I judged that I could take as a general rule that the things we conceive very clearly and very distinctly are all true, but that there only remains some difficulty in properly discerning which are the ones that we distinctly conceive.
Following this, reflecting upon the fact that I doubted and that, as a consequence, my being was not utterly perfect (for I saw clearly that it is a greater perfection to know than to doubt), I decided to search for the source from which I had learned to think of a thing more perfect than myself; and I readily knew that this ought to originate from some nature that was in effect more perfect. As to those thoughts of mine that were of many other things outside me — such as the sky, the earth, light, heat, and a thousand other things — I was not quite so anxious to know where they came from, since, having noticed nothing in them that seemed to me to make them superior to me, I could believe that, if they were true, they were dependencies of my nature, to the extent that it had any perfection; and that if they were not true, I received them from nothing, that is, they were in me because I had some defect. But the same could not hold for the idea of a being more perfect than my own; for the receiving of this idea from nothing is a manifest impossibility; and since it is no less a contradiction that something more perfect should follow from and depend upon something less perfect than that something can come from nothing, I certainly could not obtain it from myself. It thus remained that this idea was placed in me by a nature truly more perfect than I was, and even that it had within itself all the perfections of which I could have any idea, that is, to put my case in a single word, that this nature was God. To this I added that, since I knew of some perfections that I did not possess, I was not the only being in existence (here, if you please, I shall use freely the language of the School), but that of necessity it must be the case that there is something else more perfect, upon which I depended, and from which I acquired all that I had. For, had I been alone and independent of everything else, so as to have derived from myself all of that small allotment of perfection I had through participation in the perfect being, I would have been able for the same reason to give myself the remainder of what I knew was lacking in me; and thus I would be infinite, eternal, unchanging, all-knowing, all-powerful-in short, I would have all the perfections I could discern in God. For, following from the reasonings I have just given, to know the nature of God, as far as my own nature was able, I had only to consider each thing about which I found an idea in myself, whether or not it was a perfection to have them, and I was certain that none of those that were marked by any imperfection were in this nature, but that all other perfections were. So I observed that doubt, inconstancy, sadness and the like could not be in him, given the fact that I would have been happy to be exempt from them. Now, over and above that, I had ideas of several sensible and corporeal things; for even supposing that I was dreaming and that everything I saw or imagined was false, I still could not deny that the ideas were not truly in my thought. But since I had already recognized very clearly in my case that intelligent nature is distinct from corporeal nature, taking into consideration that all composition attests to dependence and that dependence is manifestly a defect, I therefore judged that being composed of these two natures cannot be a perfection in God and that, as a consequence, God is not thus composed. But, if there are bodies in the world, or intelligences, or other natures that were not entirely perfect, their being ought to depend on God's power, inasmuch as they cannot subsist without God for a single moment.
After this, I wanted to search for other truths, and, having set before myself the object dealt with by geometricians, which I conceived to be like a continuous body or a space indefinitely extended in length, breadth, and height or depth, divisible into various parts which could have various shapes and sizes and be moved or transposed in all sorts of ways (for all this the geometricians take for granted in their object), I ran through some of their simplest proofs. And having noticed that this great certitude that everyone attributes to them is founded only on the fact that one conceives them evidently conforming to the rule that I mentioned earlier, I also noted that there had been nothing in them that assured me of the existence of their object. For I saw very well that by supposing, for example, a triangle, it is necessary for its three angles to be equal to two right angles; but I did not see anything in all this which would assure me that any triangle existed. On the other hand, returning to an examination of the idea I had of a perfect being, I found that existence was contained in it, in the same way as the fact that its three angles are equal to two right angles is contained in the idea of a triangle, or that, in the case of a sphere, all its parts are equidistant from its center, or even more evidently so; and consequently, it is, at the very least, just as certain that God, who is a perfect being, is or exists, as any demonstration in geometry could be.
But what makes many people become persuaded that it is difficult to know this (i.e., the existence of the perfect being), and also even to know what kind of thing their soul is, is that they never lift their minds above sensible things and that they are so much in the habit of thinking about only what they can imagine (which is a particular way of thinking appropriate only for material things), that whatever is not imaginable seems to them to be unintelligible. This is obvious enough from what even the philosophers in the Schools take as a maxim: that there is nothing in the understanding that has not first been in the senses (where obviously the ideas of God and the soul have never been). And it seems to me that those who want to use their imagination to comprehend these things are doing the same as if, to hear sounds or to smell odors, they wanted to use their eyes, except for this difference: the sense of sight assures us no less of the truth of its objects than do the senses of smell or hearing, whereas neither our imagination nor our sense could ever assure us of anything if our understanding did not intervene.
Finally, if there are men who have not yet been sufficiently persuaded of the existence of God and their soul by means of the reasons I have brought forward, I would very much like them to know that all the other things they thought perhaps to be more certain — such as having a body, there being stars and an earth, and the like — are less certain. For although one might have a moral certainty about these things, which is such that it seems outrageous for anyone to doubt it, yet, while it is a question of metaphysical certitude, it seems unreasonable for anyone to deny that there is a sufficient basis for one's not being completely certain about the subject, given that one can, in the same fashion, imagine that while asleep one has a different body and that one sees different stars and a different earth, without any of it being the case. For how does one know that the thoughts that come to us in our dreams are more false than the others, given that often they are no less vivid or express? Let the best minds study this as much as they please, I do not believe they can give any reason that would suffice to remove this doubt, were they not to presuppose the existence of God. For first of all, even what I have already taken for a rule — namely that all the things we very clearly and very distinctly conceive are true — is certain only because God is or exists, and is a perfect being, and because all that is in us comes from him. Thus it follows that our ideas or our notions, being real things and coming from God, insofar as they are clear and distinct, cannot to this extent fail to be true. Thus, if we have ideas sufficiently often that contain falsity, this can only be the case with respect to things that have something confused or obscure about them, since in this regard they participate in nothing; that is, they are thus in us in such a confusion only because we are not perfect. And it is evident that there is no less a contradiction that falsity or imperfection, as such, proceed from God, than that truth or perfection proceed from nothing. But if we did not know that all that is real and true in us comes from a perfect and infinite being, however clear and distinct our ideas may be, we would have no reason that assured us that they had the perfection of being true.
But after the knowledge of God and the soul has thus rendered us certain of this rule, it is very easy to know that the dreams we imagine while asleep ought in no way make us doubt the truth of the thoughts we have while awake. For if it should happen, even while one is asleep that someone has a very distinct idea, as, for example, when a geometrician invents a new demonstration, his being asleep does not impede its being true. And as to the most common error of our dreams, which consists in the fact that they represent to us various objects in the same way as our exterior senses do, it is of no importance that it gives us the occasion to question the truth of such ideas, since they can also deceive us just as often without our being asleep — as when those with jaundice see everything as yellow-colored, or when the stars or other distant bodies appear to us a great deal smaller than they are. In short, whether awake or asleep, we should never allow ourselves to be persuaded except by the evidence of our reason. And it is to be noted that I said this of our reason, and not of our imagination or our senses. For, although we see the sun very clearly, we should not on that account judge that it is only as large as we see it; and we can very well imagine distinctly the head of a lion grafted on the body of a goat, without necessarily concluding for that reason that there existed a chimera; for reason does not suggest to us that what we thus see or imagine is true. But it does suggest to us that all our ideas or notions ought to have some foundation in truth; for it would not be possible that God, who is all perfect and entirely truthful, would have put them in us without that. And because our reasonings are never so evident nor so complete while we are asleep as they are while we are awake, even though our imaginations are sometimes just as, or even more, vivid and express when asleep, reason also suggests to us that our thoughts are unable all to be true, since we are not all-perfect; what truth there is in them ought infallibly to be found in those we have when awake rather than those we have in our dreams.