Descartes, a genius made to blaze new paths and to go astray in them, supposed with some other philosophers that God is the only efficient cause of motion, and that every instant He communicates motion to all bodies. But this opinion is but an hypothesis which he tried to adjust to the light of faith; and in so doing he was no longer attempting to speak as a philosopher or to philosophers. Above all he was not addressing those who can be convinced only by the force of evidence.

The human body is a machine which winds its own springs.

One needs only eyes to see the necessary influence of old age on reason.

The soul follows the progress of the body, as it does the progress of education.

The mind, like the body, has its contagious diseases and its scurvy. ...We catch everything from those with whom we come in contact; their gestures, their accent, etc.

A brilliant man is his own best company, unless he can find other company of the same sort.

The, diverse states of the soul are always correlative with those of the body.

In general, the form and the structure of the brains of quadrupeds are almost the same as those of the brain of man...

A mere nothing, a tiny fibre, something that could never be found by the most delicate anatomy, would have made of Erasmus and Fontenelle two idiots, and Fontenelle himself speaks of this very fact in one of his best dialogues.

Among animals, some learn to speak and sing; they remember tunes, and strike the notes as exactly as a musician. Others, for instance the ape, show more intelligence... would it be absolutely impossible to teach the ape a language? I do not think so.

Let us... take in our hands the staff of experience... To be blind and to think that one can do without this staff is the worst kind of blindness.

Man... whatever the origin of his soul, if it is pure, noble, and lofty, it is a beautiful soul which dignifies the man endowed with it.

The Christian Scholastics... might have shown that God Himself said that He had "imprinted an active principle in the elements of matter (Gen. i; Is. lxvi).

We have now but to prove a third attribute: I mean the faculty of feeling which the philosophers of all centuries have found in this same substance. ...[T]he Cartesians have made, in vain, to rob matter of this faculty. But in order to avoid insurmountable difficulties, they have flung themselves into a labyrinth from which they have thought to escape by this absurd system "that animals are pure machines."An opinion so absurd has never gained admittance among philosophers... Experience gives us no less proof of the faculty of feeling in animals than of feeling in men.

There comes up another difficulty which more nearly concerns our vanity: namely, the impossibility of our conceiving this property [the faculty of feeling] as a dependence or attribute of matter.

We know in bodies only matter, and we observe the faculty of feeling only in bodies: on what foundation then can we erect an ideal being, disowned by all our knowledge?

We must admit, with the same frankness, that we are ignorant whether matter has in itself the faculty of feeling, or only the power of acquiring it by those modifications or forms to which matter is susceptible; for it is true that this faculty of feeling appears only in organic bodies.This is then another new faculty which might exist only potentially in matter, like all the others which have been mentioned; and this was the hypothesis of the ancients, whose philosophy, full of insight and penetration, deserves to be raised above the ruins of the philosophy of the moderns.

Ancient philosophy will always hold its own among those who are worthy to judge it, because it forms... a system that is solid and well articulated like the body, whereas all these scattered members of modern philosophy form no system.

It is not enough for a wise man to study nature and truth; he should dare state truth for the benefit of the few who are willing and able to think.

I reduce to two the systems of philosophy which deal with man's soul. The first and older system is materialism; the second is spiritualism.

If there is a revelation, it can not then contradict nature.

Let us not limit the resources of nature; they are infinite, especially when reinforced by great art.

What was man before the invention of words and the knowledge of language? An animal..

Man has been trained in the same way as animals. He has become an author, as they became beasts of burden.

With regard to the questions with which we are concerned, Lamettrie stands at the commencement of the whole series.

That the true connection could so long be misrepresented is, next to the influence of Hegel and his school, chiefly to be attributed to the resentment excited by Lamettrie's attack upon the Christian morality. People forgot, in consequence, his theoretical writings; and the calmest and most serious of them, including the 'Natural History of the Soul,' were most completely forgotten.

As a friend, he may have been obliging and self-sacrificing; as an enemy, he was, as in particular had to experience, malicious and low in the choice of his means.

In the year 1742 he... received there a position as surgeon to the Guard. In this capacity he made a campaign in Germany, and... was seized by a violent fever, and used this opportunity in order to institute observations upon himself as to the influence of quickened circulation upon thought. He came to the conclusion that thought is nothing but a consequence of the organisation of our mechanism. ...[H]e tried during his convalescence to explain the mental functions by the help of anatomy, and he had his conjectures printed under the title of a 'Natural History of the Soul.' The regimental chaplain sounded the alarm, and soon a universal cry of indignation was raised... His books were recognised as heretical, and he could no longer continue to be surgeon of the Guard. ...about the same time ...writing a satire on his rivals, the foremost Paris practitioners. ...He fled in the year 1746 to Leyden. Here he wrote ...a new satire upon the charlatanism and ignorance of doctors, and soon afterwards (1748) appeared also his 'Homme Machine.'

The 'Natural History of the Soul' begins by showing that as yet no philosopher, from Aristotle down to Malebranche, had been able to account for the nature of the soul.

Very ingeniously Lamettrie observes that at bottom I am immediately certain only of my own feeling. That other men also feel, I conclude with very much stronger conviction from the expression of their feelings in gestures and cries than from their articulate speech. That energetic language of the emotions is, however, the same in the animals as in men, and it carries with it much stronger proof than all the sophisms of Descartes. ...[T]he internal organisation of man and of the animals offers a perfect analogy. If it remains for the present incomprehensible how the capability of feeling can be an attribute of matter, it is with this, as with a thousand other puzzles, in which, according to an idea of Leibniz, instead of the thing itself we see only the veil that hides it. ...[S]ensation, like motion, must at all events potentially belong to all matter. So thought the ancients, whose philosophy is preferred by all capable minds to the inadequate attempts of the moderns. After this Lamettrie passes to the doctrine of substantial forms...

Whether the soul occupies only a particular point or a circuit we do not know, but as all nerves do not meet in one point in the brain, the former supposition is improbable. All knowledge is in the soul only at the moment in which it is affected by it; all preservation of it is to be resolved into organic conditions. Thus the 'Natural History of the Soul,' starting from ordinary notions, gradually leads us on into Materialism, and it is concluded that... which feels must also be material. How this comes about Lamettrie too does not know; but why should we (according to Locke) limit the omnipotence of the Creator because of our ignorance? Memory, imagination, passions, and so on, are then explained in a thoroughly materialistic way.

The very much shorter section on the rational soul discusses freedom, reflection, judgment, and so on, with the same strong leaning to Materialism there follows a chapter over which is written, "...religious faith alone can confirm our belief as to the existence of a rational soul." ...The object... is to show how metaphysics and religion came to adopt the notion of a soul, and it concludes by saying that true philosophy freely confesses that the... soul is unknown to her. ...Mention is also made of Voltaire's phrase, 'I am body, and I think;' and Lamettrie refers with pleasure to the way in which Voltaire scoffs at the Scholastic proof for the proposition that no matter can think.

The last chapter... bears the title, " Narratives which prove that all Ideas are derived from the Senses." ...Everywhere the consequence is drawn that only the education he receives through the senses makes man man, and gives him what we call the soul, while no development of the mind from within outwards ever takes place.

Hettner forgets his own chronological data when he maintains that Lamettrie, instigated chiefly by Diderot's 'Pensées Philosophiques,' wrote in 1745 the 'Histoire Naturelle de l'Ame,' and in 1748 'L'Homme Machine;' and in Schlosser's ' History of the World' we may read that Lamettrie was a very ignorant man, who had the impudence to pass off the discoveries and observations of others as his own. Only that in nearly every case where we find a striking similarity of ideas between Lamettrie and any famous contemporary of his, the former had an indisputable priority!

He who has the most imagination should be regarded as having the most intelligence or genius, for all these words are synonymous...

A geometrician has learned to perform the most difficult demonstrations and calculations, as a monkey has learned to take his little hat off and on...

As a violin string or a harpsichord key vibrates and gives forth sound, so the cerebral fibres, struck by waves of sound, are stimulated to render or repeat the words that strike them.

The sciences that are expressed by numbers or by other small signs, are easily learned; and... this facility rather than its demonstrability is what has made the fortune of algebra.

Everything is the work of imagination, and... all the faculties of the soul can be correctly reduced to pure imagination...

Why should we divide the sensitive principle which thinks in man? ...For a thing that is divided can no longer without absurdity be regarded as indivisible.

Imagination is the soul, since it plays all the roles of the soul.

Man's preeminent advantage is his organism. ...Only through nature do we have any good qualities; to her we owe all that we are.

Whatever the virtue may be, from whatever source it may come, it is worthy of esteem... Mind, beauty, wealth, nobility, although the children of chance, all have their own value, as skill, learning and virtue have theirs.

If one's organism is... the preeminent advantage, and the source of all others, education is the second. The best made brain would be a total loss without it...

In very different fashion does the book set to work that already in its very title declares that man is a machine. While the 'Natural History of the Soul' was cautious, cunningly arranged, and only gradually surprising us with its results, here, on the contrary,the final conclusion is expressed at the outset of the work. While the 'Natural History of the Soul' allied itself with the whole Aristotelian metaphysics only in order to prove by degrees that the soul is but an empty form, into which we may pour a materialistic content, here we no longer deal in all those fine distinctions.

If we demonstrate this moving principle, if we show that matter, far from being as indifferent as it is supposed to be, to movement and to rest, ought to be regarded as an active, as well as a passive substance, what resource can be left to those who have made its essence consist in extension?

The ancients, persuaded that there is no body without a moving force, regarded the substance of bodies as composed of two primitive attributes. It was held that, through one of these attributes, this substance has the capacity for moving and, through the other, the capacity for being moved.

Before Descartes, some of the ancients made the essence of matter consist in solid extension. But this opinion, of which all the Cartesians have made much, has at all times been victoriously combated...

Write as if thou wert alone in the universe and hadst nothing to fear from the jealousies and prejudices of the people. Otherwise thou wilt miss thy purpose.

A good prescription is still more profitable than an .