Reply of DESCARTES

LETTER II.

SIR,

There was no need for the ceremony that your friend wished to employ; those of his merit and intellect have no need of mediators, and I shall always count it a favor when persons like him do me the honor of consulting me about my writings. I beg you to rid him of this scruple; but for this time, since he has wished it, I shall take the trouble of addressing my Replies to him through you.

Firstly, it is true that if I had said absolutely that one must hold to the opinions that one has once decided to follow, even if they were doubtful, I would be no less reprehensible than if I had said that one must be stubborn and obstinate; because holding to an opinion is the same as persevering in the judgment one has made of it. But I said something quite different, namely that one must be resolute in one’s actions, even when one remains irresolute in one’s judgments (see page twenty-four, line 8), and follow no less constantly the most doubtful opinions—that is to say, act no less constantly according to opinions that one judges doubtful, when one has once determined upon them, that is to say, when one has considered that there are no others that one judges better, or more certain, than if one knew those to be the best; as indeed they are under that condition (see page twenty-six, line 15). And there is no fear that this firmness in action will engage us more and more in error or in vice, inasmuch as error can only be in the understanding, which I suppose nonetheless remains free, and considers as doubtful what is doubtful. Besides, I chiefly relate this rule to the actions of life that admit of no delay, and I use it only provisionally (page 24, line 10), with the intention of changing my opinions as soon as I can find better ones, and of losing no opportunity of seeking them (page 29, line 8). Moreover, I was obliged to speak of this resolution and firmness concerning actions, both because it is necessary for the peace of conscience, and to prevent anyone from blaming me for having written that, in order to avoid prejudice, one must once in one’s life rid oneself of all the opinions one has previously received into one’s belief: for apparently it would have been objected to me that this so universal doubt might produce great irresolution and great disorder in morals. So that it does not seem to me that I could have used more circumspection than I did, in placing resolution, insofar as it is a virtue, between the two vices contrary to it, namely indetermination and obstinacy.

2. It does not seem to me at all to be a fiction, but a truth that ought not to be denied by anyone, That there is nothing that is entirely in our power except our thoughts; at least taking the word thought as I do, for all the operations of the soul; so that not only meditations and volitions, but even the functions of seeing, hearing, determining oneself to one movement rather than another, etc., insofar as they depend on it, are thoughts. And there is absolutely nothing except the things comprehended under this word that is properly attributed to man in the language of Philosophy: for as for the functions that belong to the body alone, one says that they take place in man, and not by man. Besides, by the word entirely (page 27, line 3), and by what follows, namely, That, when we have done our best touching external things, all that fails to succeed is in our regard absolutely impossible; I sufficiently show that I did not mean by this that external things were not at all in our power, but only that they are in it only insofar as they can follow from our thoughts, and not absolutely, nor entirely, because there are other powers outside us that can hinder the effects of our designs. Indeed, to express myself better, I have joined together these two words in our regard and absolutely, which Critics might criticize as contradicting each other, were it not that the understanding of the sense reconciles them. Now, notwithstanding that it is very true that no external thing is in our power except insofar as it depends on the direction of our soul, and that nothing is absolutely so except our thoughts; and that it seems to me no one can find it difficult to agree to this, when he expressly thinks about it; I have nonetheless said that one must accustom oneself to believe it, and even that a long exercise and a frequently repeated meditation is needed for this purpose; the reason for which is that our appetites and passions continually dictate the contrary to us; and that we have so many times experienced from our childhood that by crying, or commanding, etc., we have made ourselves obeyed by our nurses, and have obtained the things we desired, that we have imperceptibly persuaded ourselves that the world was made only for us, and that all things were due to us: in which those who are born great and fortunate have the most occasion to deceive themselves; and one also sees that it is ordinarily they who bear the disgraces of fortune most impatiently. But there is no occupation, it seems to me, more worthy of a Philosopher, than to accustom oneself to believe what true reason dictates, and to guard against the false opinions that one’s natural appetites persuade.

3. When one says, I breathe, therefore I am, if one wishes to conclude one’s existence from the fact that breathing cannot be without it, one concludes nothing, because one would first have to have proved that it is true that one breathes, and that is impossible unless one has also proved that one exists. But if one wishes to conclude one’s existence from the feeling, or the opinion, that one breathes; so that even if this opinion were not true, one nonetheless judges that it is impossible that one should have it if one did not exist, one concludes very well; because this thought of breathing then presents itself to our mind before that of our existence, and we cannot doubt that we have it while we have it (see page 36, line 22). And it is no other thing to say in this sense, I breathe therefore I am, than I think therefore I am. And if one pays attention, one will find that all the other propositions from which we can thus conclude our existence come back to the same thing: so that by them, one does not prove the existence of the body—that is to say, that of a nature that occupies space, etc.—but only that of the soul, that is to say, of a nature that thinks; and although one may doubt whether it is not the same nature that thinks and that occupies space—that is to say, that is both intellectual and corporeal—nevertheless one knows it by the path I have proposed only as intellectual.

4. From this alone, that one conceives clearly and distinctly the two natures of the soul and the body as diverse, one knows that they are truly diverse, and consequently that the soul can think without the body, notwithstanding that when it is joined to it, it may be troubled in its operations by the bad disposition of the organs.

5. Although the Pyrrhonians concluded nothing certain from their doubts, it does not follow that one cannot. And I would try here to show how one can use them to prove the existence of God, by clarifying the difficulties I have left in what I have written about it; but I have been promised that I will soon be sent a collection of all that can be doubted on this subject, which will perhaps give me occasion to do it better: that is why I beg the one who made these Remarks to allow me to defer until I have received it.

6. It is certain that the resemblance that exists between most of the actions of beasts and our own has given us from the beginning of our life so many occasions to judge that they act by an interior principle similar to that which is in us—that is to say, by means of a Soul that has feelings and passions like ours—that we are all naturally prejudiced in favor of this opinion; and, whatever reasons one may have for denying it, one can scarcely say openly what the truth is, without exposing oneself to the ridicule of children and weak minds. But for those who wish to know the truth, they must above all distrust the opinions with which they have thus been prejudiced from childhood: and in order to know what one ought to believe concerning this one, one should, it seems to me, consider what judgment a man would make of it who had been brought up all his life in some place where he had never seen any other animals than men, and where, having greatly devoted himself to the study of Mechanics, he had made, or helped to make, several automata, some of which had the figure of a man, others of a horse, others of a dog, others of a bird, etc., and which walked, ate, and breathed; in short, which imitated as far as possible all the other actions of the animals whose likeness they bore, not omitting even the signs we use to testify to our passions, such as crying out when they were struck, fleeing when some great noise was made around them, etc.; so that he would often have found himself at a loss to distinguish between real men and those who had only their figure; and to whom experience would have taught that there are only the two means I have explained on page 57 of my Method for recognizing them, one of which is that never, except by chance, do these automata respond, either in words or even by signs, appropriately to what is asked of them: and the other, that although often the movements they make are more regular and more certain than those of the wisest men, they nevertheless fail in several things that they ought to do to imitate us, more than the most insane would. One must, I say, consider what judgment this man would make of the animals that are among us when he saw them; especially if he were imbued with the knowledge of God, or at least had remarked how much all the industry that men use in their works is inferior to that which Nature shows in the composition of plants; and in that she fills them with an infinity of little conduits imperceptible to the eye, through which she makes certain liquors rise little by little, which, having reached the tops of their branches, mix there, arrange themselves, and dry there in such a way that they form leaves, flowers, and fruits. So that he would firmly believe that if God or Nature had formed some automata that imitated our actions, they would imitate them more perfectly, and would be incomparably more ingeniously made, than any of those that can be invented by men. Now there is no doubt that this man, seeing the animals that are among us, and noticing in their actions the same two things that make them different from ours, which he had been accustomed to notice in his automata, would not judge that there was in them any true feeling, or any true passion, as in us, but only that they were automata, which, being composed by Nature, would be incomparably more accomplished than any of those he had previously made himself. So that there only remains here to consider whether the judgment he would thus make with knowledge of the cause, and without having been prejudiced by any false opinion, is less credible than that which we made when we were children, and which we have since retained only by custom, basing it solely on the resemblance that exists between some exterior actions of animals and our own, which is by no means sufficient to prove that there is also one between the interior ones.

7. I have tried to make known that the Soul is a substance really distinct from the body, which suffices, it seems to me, in speaking to those who acknowledge that God is the creator of all things, to make them also acknowledge that our Souls must necessarily be created by Him. And those who have assured themselves of His existence by the path I have shown will not fail to recognize Him as such.

8. I did not say that light was extended like a stick, but like the actions or movements that are transmitted by a stick. And although movement does not take place in an instant, nonetheless each of its parts can be felt at one end of a stick at the same instant (that is to say, at exactly the same time) that it is produced at the other end. I did not say either that light was like the must from the vat, but like the action by which the highest parts of this must tend downwards; and they tend downwards exactly in a straight line, notwithstanding that they cannot move so exactly in a straight line, as I said page 8, line 1.

9. Since I have professed not to wish to explain the foundations of Physics (page 76, line 19), I did not think I had to explain the subtle matter of which I have spoken more distinctly than I did.

10. Although water remains liquid only because its parts are maintained in their agitation by the subtle matter that surrounds them, that does not prevent it from becoming so when they are agitated by some other cause. And provided one knows that fire, having the force to move the parts of terrestrial bodies that approach it, as one sees with the eye in many cases, must a fortiori move those of subtle matter, because they are smaller and less joined together, which are the two qualities for which a body can be called more subtle than others, one will find no difficulty in this article.

11. It is well known that I do not pretend to persuade that the parts of water have the figure of some animals; but only that they are long, smooth, and flexible. Now if one can find some other figure by which one explains all their properties, as one does by this one, I am quite willing that it be attributed to them; but if one cannot, I do not see what difficulty one makes in imagining them in this one, as soon as in any other, seeing that they must necessarily have some figure, and that this one is among the simplest. As for air, although I do not deny that there may be some of its parts that also have this figure, nonetheless there are several things that show sufficiently that they cannot all have it: among others, it would not be so light as it is, because these sorts of parts easily arrange themselves next to each other, without leaving much space around them, and thus must compose a fairly massive and heavy body, such as water is, or else it would be much more penetrating than it is, for one sees that it is hardly more so than water, or even in several cases that it is less so; it could not either dilate or condense by degrees so easily as it does, etc.

12. It seems to me that what this article contains is the same as if, because I had said that the pain one feels in receiving a sword cut is not in the sword as in the sense, but is only caused by the figure of its cutting edge or point, by the hardness of its matter, and by the force with which it is moved; one objected to me that other bodies that have a cutting edge in the same way could also cause pain; and that those that have other figures could not be felt, especially those that are soft, and not hard like a sword. And finally that pain is nothing else in this sword than its external figure, and not an internal quality; and that the force it has to prevent its scabbard from breaking when it is inside consists only in the action by which it wounds, and in its figure. In consequence of which one easily sees what I have to reply, namely that bodies whose parts have the same size, figure, hardness, etc. as those of salt, will have the same effect, in what concerns taste; but that this being so, one cannot suppose that these bodies are insipid: for to be insipid is not to have no taste in oneself, but to be not apt to cause it. And liquids whose parts have other figures, or sizes, etc. do not have the taste of salt, but they can have others, although not so strong and pungent, if their parts are softer, just as the pain of a bruise is not the same as that of a cut; and one cannot cause as much with a feather as with a sword, because it is of a softer matter. Finally, I do not see why one wishes taste to be a more internal quality in salt than pain is in a sword. And as for the force salt has to keep things from corrupting, it consists neither in its pungency, nor in the figure of its parts, but in their hardness or stiffness, just as it is the stiffness of the sword that prevents the scabbard from breaking, and their figure contributes only insofar as it makes them apt to enter the pores of other bodies; as it is also the figure of the sword that makes it apt to enter its scabbard.

13. It is not enough that a body be equally thick at both ends for it not to sink into water; but besides that, it must not be extraordinarily thick, and it must be laid flat on its surface; as one sees that a small steel needle laid on water can float on it, which a very large one will not do, nor the same one placed otherwise, nor a piece of steel of the same weight but of another figure, of which one end is much thicker than the other.

14. I grant this last article, and one sees the experience of it in that sea water is desalinated when it passes through a great deal of sand. But it is to be noted that it is not enough to desalinate it to try to make it pass through a body whose pores are very narrow, because their entrances being immediately blocked by the first parts of salt that present themselves, those of fresh water could find no passage there: that is why one should rather make it flow through some body that has pores large enough in which there are angles or recesses, that can retain the parts of salt; and this body must be very large and very thick, so that the water, being able to leave its salty parts there only one at a time, as they enter some recesses where they stop, may have the leisure to leave them all before having traversed it.

15. It is true that as for spelling, it is for the Printer to defend it; for I desired nothing else from him in that regard, except that he follow usage: and just as I did not have him remove the p from corps, or the t from esprits, when he had put them there; so I did not take care to have him add them when he left them out, because I did not notice that he had done so in any passage where it could cause ambiguity. Moreover, I have no design to reform French spelling, nor would I wish to advise anyone to learn it from a book printed at Leyden; but if I must here give my opinion on it, I believe that if one followed pronunciation exactly, it would bring much more convenience to foreigners for learning our language than the ambiguity of some equivocations would cause inconvenience to them or to us: for it is in speaking that languages are composed rather than in writing; and if there occurred in pronunciation some equivocations that often caused ambiguity, usage would immediately change something to avoid it. I also beg you to have my replies favorably received by your friend—I mean to be yourself their defender, and to supply my shortcomings for me; this will oblige me to remain,

SIR,

Your most humble and most devoted

servant, DESCARTES.