Meet the Materialists, part 2: Julien LaMettrie and Man a Machine
A key point of my book Darwin Day in America is that materialism did not begin (or end) with Charles Darwin.
One of the pre-Darwin champions of materialism I cover in my book is physician Julien Offray de la Mettrie (1709-1751), author of the provocative tract Man a Machine (L'Homme Machine), published in 1748. According to La Mettrie, "the human body is a machine which winds its own springs" and the "the diverse states" of the human mind "are always correlative with those of the body." In other words, human beings are mechanisms whose rational life is completely dependent on physical causes. Those causes include everything from raw meat to heredity.
In what has to be one of the more interesting passages in culinary analysis, La Mettrie opined:
Raw meat makes animals fierce, and it would have the same effect on man. This is so true that the English who eat meat red and bloody, and not as well done as ours, seem to share more or less in the savagery due to this kind of good.
A substantial part of La Mettrie's treatise was devoted to attacking the belief that an unbridgeable gulf separated human beings from animals. According to La Mettrie, there was nothing mysterious in how to raise apes to men, because there was nothing mysterious in how men acquired their own rational faculties:
Man has been trained in the same way as animals. He has become an author, as they became beasts of burden. 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, and to mount his tame dog.
Underlying every part of Man a Machine is La Mettrie's steadfast faith that there is no mystery in attributing mind to matter. Indeed, La Mettrie asserted that "given the least principle of motion, animated bodies will have all that is necessary for moving, feeling, thinking, repenting."
More than a century later, the kind of extreme reductionist thinking championed by La Mettrie was developed in a far more convincing manner by Charles Darwin in his book The Descent of Man. You can read about Darwin's effort to apply materialism to human beings and human culture in "Darwin's Revolution," chapter 2 of Darwin Day in America.