OUTLINES AND NOTES.
LA METTRIE’S RELATION TO HIS PREDECESSORS AND TO HIS SUCCESSORS.
I. The Historical Relation of La Mettrie to René Descartes (1596–1650).
The most direct source of La Mettrie’s work, if the physiological aspect of his system is set aside, is found in the philosophy of Descartes. In fact it sometimes seems as if La Mettrie’s materialism grew out of his insistence on the contradictory character of the dualistic system of Descartes. He criticises Descartes’s statement that the body and soul are absolutely independent, and takes great pains to show the dependence of the soul on the body. Yet though La Mettrie’s system may be opposed to that of Descartes[1] from one point of view, from another point of view it seems to be a direct consequence of it. La Mettrie himself recognizes this relationship and feels that his doctrine that man is a machine, is a natural inference from Descartes’s teaching that animals are mere machines.[2] Moreover La Mettrie carries on Descartes’s conception of the body as a machine, and many of his detailed discussions of the machinery of the body seem to have been drawn from Descartes.
It should be noted that La Mettrie did justice to Descartes, and realized how much all philosophers owed to him. He insisted moreover that Descartes’s errors were due to his failure to follow his own method.[3] Yet La Mettrie’s method was different from that of Descartes, for La Mettrie was an empiricist[4] without rationalistic leaning. As regards doctrine: La Mettrie differed from Descartes in his opinion of matter. Since he disbelieved in any spiritual reality, he gave matter the attributes of motion and thought, while Descartes insisted that the one attribute of matter is extension.[5] It was a natural consequence of La Mettrie’s disbelief in spiritual substance that he could throw doubt on the existence of God.[6] On the other hand the belief in God was one of the foundations of Descartes’s system. La Mettrie tried to show that Descartes’s belief in a soul and in God was merely designed to hide his true thought from the priests, and to save himself from persecution.[7]