A Discourse on the Method

by René Descartes

The Collège had an impressive and rigorous curriculum, which included the university arts course (the so-called trivium of grammar, logic, and rhetoric, and quadrivium of arithmetic, geometry, music, and astronomy), which was taught as a preparation for degrees in the higher faculties of theology, law, and medicine. This curriculum had been codified and published by the Jesuits in 1599, in its Ratio studiorum: it integrated what are now known as the humanities (classical literature, history, drama, and so forth) with scholastic philosophy and theology.

By 1650 the adjective ‘Cartesian’ had emerged; it designated principally his mechanistic philosophy. This was opposed not only by Aristotelian traditionalists, but also by other radical thinkers, and was a powerful motor in the debate about the nature of matter and motion, even if none of his physical theories is now looked upon as correct. At the same time, the Discourse had another, more diffuse effect. Its radical programme, which did not require philosophical and ‘scientific’ training but only the employment of ‘good sense’, appealed to those who had not received a formal education, notably women, who felt empowered by his promotion of the image of the well-reasoning individual.

This conflict came to express itself in the opposition of those who rely on written authority (of an institution, or a text such as that of Aristotle or the Bible) and those favouring free philosophical speculation, who adopted such catch-phrases as, ‘Plato is my friend, Socrates is my friend, but truth is a greater friend’, and the ancient satirist Horace’s declaration that he was ‘not bound over to swear as any master dictates’ (nullius addictus iurare in verba magistri), which in due course was to become the motto of the Royal Society of London;

Nullius in verba

In traditional terms, certainty was established by the use of syllogistic logic; in its place, Descartes uses a form of immediate intuition which cannot be reduced to proposition, middle term, and conclusion.

that reading good books is like engaging in conversation with the most cultivated minds of past centuries who had composed them, or rather, taking part in a well-conducted dialogue in which such minds reveal to us only the best of their thoughts; that oratory is incomparably powerful and beautiful, and that poetry possesses delightful delicacy and charm;*

For conversing with those of another age is more or less the same thing as travelling. It is good to know something of the customs of different peoples in order to be able to judge our own more securely, and to prevent ourselves from thinking that everything not in accordance with our own customs is ridiculous and irrational, as those who have see nothing of the world are in the habit of doing.

But after having spent several years studying the book of the world and trying to acquire some experience of life, I took the decision one day to look into myself and to use all my mental powers to choose the paths I should follow. In this it seems to me that I have had much more success than if I had never left either my country or my books.

I am thinking therefore I exist,* was so secure and certain* that it could not be shaken by any of the most extravagant suppositions of the sceptics, I judged that I could accept it without scruple, as the first principle of the philosophy I was seeking.*

Then, too, we know from this that the true function of breathing is to bring enough fresh air into the lungs to cause the blood entering them from the right cavity into the heart, where it has been rarefied and, as it were, changed into vapour, to thicken up and convert itself once more into blood, before falling back into the left cavity; if it did not do this, it would not be fit to nourish the fire that is there. All this is confirmed by the fact that we see that animals not having lungs have also only one cavity in the heart, and that unborn children, who cannot use their lungs while in their mother’s womb, have an aperture through which blood flows from the vena cava into the left cavity of the heart, and a duct by which it comes from the vena arteriosa to the aorta, without passing through the lung.

cardiovascular physiology a la Descartes

And I had then shown what structure the nerves and the muscles of the human body must have to enable the animal spirits, being inside that body, to have the power to move its members, as we observe in the case of severed heads, which we can see moving and biting the earth shortly after having been cut off, although they are no longer animate.

For even the mind depends so much on the temperament* and disposition of the organs of the body that, if it is possible to find some way of making men in most cases wiser and more skilful than they have been hitherto, I believe that it is in medicine that it must be sought. It is true that medicine as presently practised contains little of such notable benefit; but without wishing to disparage it, I am certain that there is no one, even among those whose profession it is, who will not admit that what is known about it is almost nothing compared to what remains to be known, and that it would be possible to be free of innumerable illnesses of both body and mind, and perhaps even the decline of old age, if we knew enough about their causes and the remedies with which nature has provided us.*

We see, too, that it has almost never happened that any of their disciples have surpassed them; and I am sure that the most passionate present-day followers of Aristotle would count themselves fortunate if they had as much knowledge of nature as he had, even on the condition that they would never have more. They are like ivy, which tends never to grow higher than the trees that support it, and often even grows back down once it has reached their tops. For it seems to me that modern Aristotelians also come back down, that is, make themselves in a certain way less knowledgeable than if they had abstained from study. Not content with knowing all that is intelligibly explained in their author, they wish, in addition, to find in his writings the solution to many problems about which he says nothing and to which he perhaps never gave any thought. However, their manner of philosophizing is very convenient to those who only have mediocre minds; for the obscurity of the distinctions and the principles which they use makes it possible for them to speak about the whole range of knowledge as boldly as if they really knew it all, and to maintain everything that they say against the subtlest and shrewdest thinkers, without there being a means of causing them to change their minds. In this they seem to be like blind men who, in order to fight on equal terms against those who can see, lure them into the depths of some very dark cellar.

I will simply say that I have decided to devote the rest of my life to nothing other than trying to acquire some knowledge of nature which may be such that we may derive some rules in medicine which are more reliable than those we have had up to now; and my inclination deters me so strongly from all other sorts of project, especially those which can be only useful to some by harming others,* that if some situation arose which forced me to work on them, I do not believe that I would be capable of succeeding. On this I here am making a declaration that I know will not make me worthy of esteem in the world, but then I have no desire to gain it.