Theories Of Mind-Body Interaction
Cartesian Interactionism: Body and soul converge at the pineal gland, that certain "something" in the middle of the brain which is known to secrete melatonin. The pineal gland, Descartes (1596-1650) thought, controlled the direction of certain "spirits" to and from the brain. Without it, consciousness would not be possible.
Double Aspect Theory: The human being is indissolubly "one" substance, and it is misleading (on this view) to conceive of her in parts. But such a conception is possible, and human beings are often described as part "mind" and part "body" -- two aspects of a whole.
Dualism: The belief that human beings are made of two substances: mind (or soul) and body. The most influential version of this theory, if not the best, is that of Plato (427 BC-347 BC), who believed the soul had a pre-history and that it is essentially "imprisoned" in the human body. Humans, on this view, are seen to be inmaterial beings: that is, they are essentially their soul, or spirit. The soul is seen as the tenant to the bodily abode, its master or lord.
Epiphenomenalism: The view that the body acts upon the mind to produce thoughts and feelings, that mental states can never be the causes of bodily functions. Mind and body, on this view, do not interact. Materialism: The belief that the human is the totality of his bodily (material) parts. In the same way that an automobile is comprised of certain parts -- engine, cylinders, shock absorbers, wheels, &c. -- so the human being is comprised of limbs, flesh, blood, internal organs. The theory encounters difficulty once someone asks which "part of the whole" is involved in a given activity; for example, if someone prays to Allah for mercy, wouldn't it be every bit as absurd to say the foot and the earlobe and the bridge of the nose are praying just as much as the "soul" is? The reduction to matter and to bodily parts just doesn't seem to account for states like these, or even states of mind (emotions, feelings, attitudes). Personhood seems nobler and more magnificent than this.
Monism: The belief that every self is an incarnation of the divine, or of the unconscious, or of some impersonal deity. In Indian philosophy such a reality is referred to as Brahma.
Occasionalism: The view, as put forth by the French philosopher Malebranche (1638-1715), that mind and body function independently, but are coordinated by God, who creates a mental event which is the "occasion" for the appropriate bodily movement. Perhaps the most eccentric and easily dismissed of all the better known theories.