Descartes reaches the conclusion that the nature of the mind (a thinking, non-extended thing) is completely different from that of the body (an extended, non-thinking thing), and therefore it is possible for one to exist without the other. Descartes views are known as Cartesian Dualism as he believed that the two do interact, however he struggled to come up with a feasible answer to how this interaction was possible. His dilemma was as follows: the soul influences the body every time it exercises an act of will; a body is only influenced by being pushed however the soul cannot exert a physical force. Descartes finally concluded that all this happened in the brain, where all the bodily muscles are controlled and all the senses come together. Incorrectly he believed that everything in the brain was double except for a small part in the central cavity (the pineal gland), which he decided was the point of interaction between he body and the soul. Here, he believed, the mind moves the pineal gland, and by doing so, changes the state of the brain which produces motions. Similarly, the sensory organs all transmit their information to the pineal gland and, as a result, sensation is transmitted to the mind.
There are however problems with Dualism. One criticism of dualism is that it cannot be scientifically investigated. If the soul is a non-physical entity it cannot be scientifically proven because science only deals with the material world, all we could examine would be its effects of the world. The idea of evolution is another problem. A dualist would find it very difficult to explain how the soul has been evolved, if simpler creatures do not have souls. Another scientific problem with dualism is that it actually contradicts a basic scientific principle. Most scientists assume every change in an object occurs from a prior physical event. If pure thought can lead to action then this proposes that merely mental events can lead to physical ones.
Gilbert Ryle is a critic of dualism and calls Cartesian dualism “the doctrine of the ghost in the machine”. He says that dualists are making a category mistake, and tries to prove this using two examples. One example is as follows: a student is looking around a university. She has looked around the halls, the lecture rooms; all the buildings and finally asks “Where is the university?” This, Ryle says, is a category mistake. Instead of looking at the university as a whole she has tried to identify the university as one particular thing which it is not. Similarly, Dualists misuse their language when they talk about the soul. Just because you can name something doesn’t mean it exists as a distinct entity, the soul is a more of a descriptive word then a physical substance.
There have been suggestions to solve the body/ soul interaction problem, which don’t actually involve direct interaction. One argument is that the mind and body run in parallel like two clocks which have been at the same time. When one event happens, it does not cause the other, its simply coincidental that they occur one immediately after the other. Occasionalism is another argument which suggests that God supplies the connection between our bodies and our souls. The problem with this however is that it assumes God exists. Epiphenomenalism is the third approach. This suggests that although bodily events can cause mental events, mental events cannot cause physical ones. The soul is an epiphenomenon; lifting my arm is a physical action which only seems to be caused by thought.
In conclusion, the two main proponents of dualism were Plato and Descartes who do suggest a distinction between the body and soul but there do seem to be many other ideas to do with the interaction between the body and the soul. Plato and Descartes perhaps were the main proponents of dualism but probably not the first two have ideas about the distinction between the body and soul