Dualism (philosophy of mind)
In philosophy of mind, dualism is the assumption that mental phenomena are, in some respects, non-physical, or that the mind and body are not identical. Thus, it encompasses a set of views about the relationship between mind and matter, and is contrasted with other positions, such as physicalism, in the mind–body problem.
Aristotle shared Plato's view of multiple souls, (ψυχή psychē) and further elaborated a hierarchical arrangement, corresponding to the distinctive functions of plants, animals and people: a nutritive soul of growth and metabolism,
that all three share, a perceptive soul of pain, pleasure and desire, that only people and other animals share, and the faculty of reason, that is unique to people only.
In this view, a soul is the hylomorphic form of a viable organism, wherein each level of the hierarchy formally supervenes upon the substance of the preceding level.
Thus, for Aristotle, all three souls perish when the living organism dies. For Plato however, the soul was not dependent on the physical body; he believed in metempsychosis, the migration of the soul to a new physical body.
Dualism is closely associated with the philosophy of René Descartes (1641), which holds that the mind is a nonphysical substance. Descartes clearly identified the mind with consciousness and self-awareness and distinguished this from the brain as the seat of intelligence.
Hence, he was the first to formulate the mind–body problem in the form in which it exists today. Dualism is contrasted with various kinds of monism. Substance dualism is contrasted with all forms of materialism, but property dualism may be considered a form of emergent materialism or non-reductive physicalism in some sense.
Findings in neuroscience that concern the mind-body problem do not support dualism, and the field operates under the assumptions of physicalism.