Julien de La Mettrie is considered one of the most influential
determinists of the eighteenth century. He believed that mental processes were caused by the body. He expressed these thoughts in his most important work
Man a Machine. There he also expressed his belief that humans worked like a machine. This theory can be considered to build off the work of
Descartes and his approach to the human body working as a machine. La Mettrie believed that man, body and mind, worked like a machine. Although he helped further Descartes' view of mechanization in explaining human bodily behavior, he argued against Descartes' dualistic view on the mind. His opinions were so strong that he stated that Descartes was actually a materialist in regards to the mind. The philosopher David Skrbina considers La Mettrie an adherent of "vitalistic materialism":
Man and the animal Prior to
Man a Machine he published
The Natural History of the Soul in 1745. He argued that humans were just complex animals. He later built on that idea: he claimed that humans and animals were composed of organized matter. He believed that humans and animals were only different in regards to the complexity that matter was organized. He compared the differences between man and animal to those of high quality pendulum clocks and watches stating: "[Man] is to the ape, and to the most intelligent animals, as the planetary pendulum of
Huygens is to a watch of
Julien Le Roy". While he did recognize that only humans spoke a language, he thought that animals were capable of learning a language. He used apes as an example, stating that if they were trained they would be "perfect [men]". Some of the evidence La Mettrie presented was disregarded due to the nature of it. He argued that events such as a beheaded chicken running around, or a recently removed heart of an animal still working, proved the connection between the brain and the body. While theories did build off La Mettrie's, his works were not necessarily scientific. Rather, his writings were controversial and defiant.
Human nature He further expressed his radical beliefs by asserting himself as a determinist, dismissing the use of judges. He disagreed with Christian beliefs and emphasized the importance of going after sensual pleasure, a hedonistic approach to human behavior. He further looked at human behavior by questioning the belief that humans have a higher sense of morality than animals. He noted that animals rarely tortured each other and argued that some animals were capable of some level of morality. He believed that as machines, humans would follow the law of nature and ignore their own interests for those of others.
Influence La Mettrie most directly influenced
Pierre Jean Georges Cabanis, a prominent French physician. He worked off La Mettrie's materialistic views but modified them in order to be not as extreme. La Mettrie's extreme beliefs were rejected strongly, but his work did help influence
psychology, specifically
behaviorism. His influence is seen in the
reductionist approach of behavioral psychologists. Nonetheless, the backlash he received was so strong that many behaviorists knew very little to nothing about La Mettrie and rather built off other materialists with similar arguments.
Cybernetics and its applications to psychology are also consistent with La Mettrie's position. However, currently the psychological school most clearly influenced by La Mettrie is
cognitive science, including the
philosophy of artificial intelligence, which proposes to build robots in the image and likeness of the human being and other living beings, and even analyze the human being based on the robot analogy. ==Later life==