Rene Descartes (1596- 1650) is one of the most important philosophers of the past few centuries. One of the most widely known philosophical ideas is in his theory of Dualism in the existence of reality. Descartes tried to prove that he himself must have the basic characteristic of thinking, and that which thinks, the mind, is distinct from his body, the existence of gods, the existence of nature, of the world etc. After his death, Descartes left the ongoing mind-body problem.
             Descartes mind-body theory combines substance dualism with attribute or property dualism. Substance dualism holds that the mind or soul is a separate, non-physical entity. According to property dualism, there is no soul, distinct from the body; only the person has two irreducible and different types of properties, mental and physical. Substance dualism allows for the possibility that the soul might be able to exist apart from the body either before birth or after death. Property dualism allows for the compatibility of mental and physical causation, since the cause of an action could be explained as an event in the brain, or as a desire, emotion, or thought. Substance dualism usually demands causal interaction between the soul and the body. (Honderich, 1995)
             The mind–body problem is an issue of accounting for how minds and mental processes are related to states and processes in the body. Descartes thought of the mind to be in itself of mental substance, which thinking or consciousness is the essential nature. The nature of the body, or material substance, Descartes claimed to be spatial extendedness. Accordingly, this created two kinds of entities, one consisting of immaterial minds and material bodies; the body is extended and unthinking, while the mind is thinking and un-extended. These two entities own separate families of properties: think, willing, feeling vs. shape, size, and mass. (Honderich, 1995) D
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