Editing Mind–body dualism (section)

===Descartes and his disciples===
In his ''[[Meditations on First Philosophy]]'', [[René Descartes]] embarked upon a quest in which he called all his previous beliefs into doubt, to find out what he could be certain of.<ref name="De" /> In so doing, he discovered that he could doubt whether he had a body (it could be that he was dreaming of it or that it was an illusion created by an evil demon), but he could not doubt whether he had a mind. This gave Descartes his first inkling that the mind and body were different things. The mind, according to Descartes, was a "thinking thing" ({{langx|la|[[res cogitans]]}}), and an immaterial [[Substance theory|substance]]. This "thing" was the essence of himself, that which doubts, believes, hopes, and thinks. The body, "the thing that exists" ({{langx|la|[[res extensa]]|label=none}}), regulates normal bodily functions (such as heart and liver). According to Descartes, animals only had a body and not a soul (which distinguishes humans from animals). The distinction between mind and body is argued in ''Meditation'' VI as follows: I have a clear and distinct idea of myself as a thinking, non-extended thing, and a clear and distinct idea of body as an extended and non-thinking thing. Whatever I can conceive clearly and distinctly, God can so create.

The central claim of what is often called ''Cartesian dualism'', in honor of Descartes, is that the immaterial mind and the material body, while being ontologically distinct substances, causally interact. This is an idea that continues to feature prominently in many non-European philosophies. Mental events cause physical events, and vice versa. But this leads to a substantial problem for Cartesian dualism: How can an immaterial mind cause anything in a material body, and vice versa? This has often been called the "problem of interactionism."

Descartes himself struggled to come up with a feasible answer to this problem. In his letter to [[Elisabeth of Bohemia, Princess Palatine]], he suggested that spirits interacted with the body through the [[pineal gland]], a small gland in the centre of the brain, between the two [[Cerebral hemispheres|hemispheres]].<ref name="De" /> The term ''Cartesian dualism'' is also often associated with this more specific notion of causal interaction through the pineal gland. However, this explanation was not satisfactory: ''how'' can an immaterial mind interact with the physical pineal gland? Because Descartes' was such a difficult theory to defend, some of his disciples, such as [[Arnold Geulincx]] and [[Nicolas Malebranche]], proposed a different explanation: That all mind–body interactions required the direct intervention of God. According to these philosophers, the appropriate states of mind and body were only the ''occasions'' for such intervention, not real causes. These [[occasionalism|occasionalists]] maintained the strong thesis that all causation was directly dependent on God, instead of holding that all causation was natural except for that between mind and body.<ref name="Malebranche">[[Tad Schmaltz|Schmaltz, Tad]]. [2002] 2017. "[http://plato.stanford.edu/entries/malebranche/ Nicolas Malebranche]." ''The Stanford Encyclopedia of Philosophy'', edited by [[Edward N. Zalta|E. N. Zalta]].</ref>