The Cartesian mechanistic view of the body is the early modern idea that the body should be understood not as a thinking subject, but as a machine governed by physical laws. In Descartes’ mind-body dualism, thinking spirit (res cogitans) and extended matter (res extensa) are distinct substances. Within this framework, the mind is non-material and capable of existing independently, while the body is characterized by spatial extension and mechanical properties rather than thought.
Descartes also helped develop a mechanistic account of bodily function. In his work Treatise of Man (L’homme), he compared animal bodies to elaborate automata and treated the human body as a kind of machine created by God. He used the concept of the “human machine” to explain physiological phenomena, leaving higher functions such as will and reason to the mind. This shifted explanation of bodily processes away from soul-based accounts toward mechanical causation.
The view was later radicalized by La Mettrie in the 18th century. In Man a Machine, he argued that human beings are nothing but machines, denied the existence of the soul, and reduced mental phenomena to material processes of the brain and nervous system. According to the provided context, this mechanistic understanding of the body became influential in modern science and contributed to later biological and medical models that analyze the human organism in physico-chemical terms. It also formed part of the intellectual background for later ideas about information, mind, and mind uploading.