Final answer:
Descartes proves he is a thinking being that exists independently of his physical body through his statement 'I think, therefore I am.' He establishes a foundational belief in dualism, separating the mind as non-physical from the material body. However, modern neuroscience challenges his view, connecting thought to brain function.
Step-by-step explanation:
Rene Descartes is famous for his philosophical proposition, Cogito, ergo sum, which translates to "I think, therefore I am." This statement is a cornerstone of his argument for the existence of the self, positing that the very act of thinking is proof of one's own existence. Descartes extended this assertion to differentiate between the physical body and the non-physical mind, leading to his famous dualism theory. In his view, a thinking thing does not require a physical body and can exist independently, signifying that the mind and soul are separate from the physical realm.
In Meditations on First Philosophy, Descartes demonstrates through skepticism that certain knowledge, such as mathematical truths, remains indubitable even when senses are deceived or doubted. He believed that the soul existed prior to and was separate from the body, considering it immortal. Despite Descartes' significant contributions to philosophy, modern science has largely contradicted his views regarding the non-physical mind, showing that thought processes are intricately linked to the brain's physical structure and functioning.