Descartes not only defined skepticism, Cartesian Skepticism sharply, he also thought he knew how to overcome it, starting with his famous and infamous cogito argument. But the side effect of his remedy was that he defined another problem sharply. According to Descartes his cogito implies his existence, qua minds but not qua body. Hence, the mind-body problem arises. Welcome to Week 4, in which you will learn what the mind-body problem is. How early modern philosophers have tried to solve it? How in the second half of the 20th century, taught experiments have played the problem up. Descartes makes a distinction in principle between two substances or things that can exist independently. On the one hand, res cogitans or minds. On the other hand, it res extensa or matter, body. This view is known as substance dualism. The notion of res, chain, or substance is something that Descartes inherits from medieval scholastic philosophy, which has in turn inherited it from Aristotle's substance attribute ontology. Very roughly, there are two basic categories of entities. On the one hand, there are things or substances. On the other hand, these substances have properties and relations or attributes. Both of Descartes substances have a hallmark. Mind is res cogitans, the thinking thing. Body or matter is res extensa, the extended thing, the thing that has extension in space, it occupies space, given that they are fundamentally different. Res cogitans is not extended and res extensa doesn't think a new problem arises. The interaction problem. Think of controlled behavior, mind over matter. Mental events causing bodily movements, ending of bodily changes that can cause mental changes like drinking alcohol and feeling tipsy. How can things that are so fundamentally different, nevertheless, causally interact? The problem is reinforced by Descartes mechanical worldview, which compares the world to mechanical clock and the principle of causal closure, that physical effects can only have physical causes. Nevertheless, Descartes solution to the interaction problem is interactionism. Mind and body do interact. Although, Descartes cannot explain how the interaction takes place, he does localize it. Because in contrast to matter, the mind is indivisible. Both our sense experience and our will are unified. The interaction must take place in the pineal glands, the only part of the brain that is not cut into a left and a right hemisphere. Many of Descartes contemporaries, including princess Elizabeth of Bohemia, found Descartes' solution to the interaction problem, wanting some tried to solve or dissolve the interaction problem. In another way. Parallelism accepts substance dualism, but argues that mind and body seem to but do not really causally interact with one another. What happens on the level of the mind parallels what happens on the level of the body, so they seem to interact. But in actual fact, something completely different is really going on. That explains the appearance of interaction. Let's consider three versions of parallelism, each assigning a different role to God. Live needs explains the apparent interaction between mind and body in terms of pre-established harmony. Like two clocks can run in parallel, can display the same time, provided they've been synchronized in advance, God, the Creator, has pre-established the harmony between what happens in the minds and what happens in the bodies and brains. If Stefan punches me because he thinks I'm talking nonsense and I feel pain, or if I'm controlling my bodily movements, preparing to punch Stefan in return. There isn't any interaction taking place. God just synchronized these mental and physical events well in advance. Another parallelism is called occasionalism. According to this view, adopted by, among others, Geulincx and Malebranche, God intervenes on each occasion when there seems to be interaction between mind and body. If for example, Stefan punches me, God creates a feeling of pain in my mind. If I desire and decide to punch Stefan in return, God causes my bodily movements. Please note, this is a completely different conception of God than that of life needs. The God of healing Malebranche and the other occasionalists keeps on creating throughout history whenever the occasion arises. Thirdly, Spinoza's double-aspects view is the odd one out because it doesn't accept substance dualism. According to Spinoza, there is only one substance, God. Or on Spinoza's pantheistic conception, the worlds that necessarily manifest itself in endlessly many attributes or aspects. Human beings only have access to two of these attributes, mind and body. But just as a clock in a bell tower can have different phases that run in parallel or synchronically, because one at the same clock mechanism is steering them, the two attributes of the single substance, God's, run in parallel and only seem to interact. Finally, let's consider another strategy to deal with the interaction problem. According to epiphenomenalism, there is only one way traffic from body to mind. The mind is a by-product or epiphenomenon of the body or brain, which has no effect on the brain in turn. Appreciate the appeal these few can have on the scientists because it doesn't have to invoke non-physical causes. Unfortunately, it's not particularly informative on how physical causes can have mental effects. Moreover, it has to explain away mental causation. For instance, how our mind seems to be able to control our bodily movements.
