Rene Descartes, a French philosopher, is generally known as the Father of Modern Philosophy. For Descartes, man is essentially cogito (I think or the thinking thing). In essence, man is a thinking being. Again, as discussed above, Descartes seems to suggest that man's thinking is essentially his existence. Without it, he's nothing. Though, some scholars would suggest that man's existence is only derived from thinking. With this pronouncement, Descartes is making a demarcation between the thinking self and the body as the res extensa (extended thing).
At first glance, the body is viewed simply as an instrument of the power of thinking. As an instrument, it extends the power of the mind. The body is like a machine; the mind is like its ghost, or say, the body is to a ship; mind to its captain. Gilbert Ryle, a British philosopher, describes this mind-body dualism as the doctrine of the "ghost in the machine." Ryle defines this doctrine as the "mental and physical activity occur simultaneously but separately" (https://en.wikipedia.org/wiki/Ghost_in_the_machine). For example, if a person thinks (mental activity) he is running, then he is really or actually running (physical activity). But his mental and physical activities are separate --meaning, there is no necessary connection between what he thinks he's doing and the action done out of his thinking.
However, Descartes also admits that mind-body relation is not as simple as
that. We can not say that the
relationship between the body and soul is like that of the captain and his
ship. If the ship meets a collision, it
is only the ship that is damaged or “hurt” but not the captain who simply
observes the damage. But when my body is
hurt, I do not just observe the incident; I am involved. In his several writings, he admits that the body and soul of man is a
real unity. Yet this unity cannot be known and discussed in philosophy due to its
inherent ambiguity (Dy, 2001).
