"There is nothing in the universe but matter and motion."

(This follows Galelio's dynamic forces paradigm)

Like Gassendi before him (the nemesis of Descartes and the philosopher responsible for reintroducing Epicurus to the European world) , la Mettrie felt Descartes was simply a gutless mechanist at heart. Following his own methods, Descartes should have simply used Occam's razor to deduce that if animals were automa, then why not humans? He concluded that man and animal differed only in degree, not in kind, thereby forseeing the value of comparative psychology, and animal language research, such Doctor Patterson's experiment with teaching sign language to Koko the gorilla. He felt that intelligence was linked to brain size ratio, complexity, and education, which was leaps and bounds ahead of other materialists who saw intelligence along only one dimension, brain size.

La Mettrie concluded that man's dualistic vanities led to the misery caused by religion. Humans would in fact be better served to recognize their real materialistic roots and beginnings, to gain a better connection to the environment and himself.

"Man is not molded from a costlier clay; nature has used but one dough, and has merely varied the leaven"