One modern dualist compares the soul to a magnetic field
Descartes split reality into thinking stuff and extended stuff in 1641, and medicine largely followed his split for three centuries. Today's dualists are more inventive. William Hasker argues the soul emerges from a sufficiently complex brain, the way a magnetic field arises from a magnet, yet can act back on what produced it.
Dualism is the claim either that mental phenomena are not physical or that mind and body are distinct and separable. Its ancient forms were layered. Aristotle described a nutritive soul shared by plants, animals and people, a perceptive soul of pleasure and desire shared by animals and people, and reason unique to humans; the first two die with the body, but an intellective part endures. Plato went further, holding that souls migrate into new bodies.
Descartes gave the problem its modern shape. He treated the mind as a non-spatial substance identified with consciousness and self-awareness, able to exist outside the body, while the body cannot think. After the scientific upheavals of the 17th century, bodies were studied piece by piece through anatomy and physiology, and the mind–body split remained the biomedical model for three hundred years. Substance dualism still has defenders, including Richard Swinburne and E. J. Lowe, most of whom accept interactionism, the view that mind and body affect each other.
Followers of Thomas Aquinas offer a twist. J. P. Moreland describes a single substance, the soul, with the body as an ensouled physical structure depending on it. Edward Feser and Paul Chutikorn argue Aquinas was not really a substance dualist at all, and that recognising a duality within one unified substance may dissolve the puzzle of how two different substances interact.
Weaker versions keep one kind of stuff but two kinds of property or description. Property dualists say mental properties emerge when matter is organised as living bodies are, and may not reduce to physics. Epiphenomenalists add that such mental states are causal dead ends, produced by the brain but producing nothing. John Searle calls his own view biological naturalism and insists it only looks like property dualism. Donald Davidson and Jerry Fodor defend predicate dualism: talk of beliefs and desires cannot be translated into physical vocabulary, contrary to eliminativists who expect such words to disappear.
Source: Mind–body dualism
