Property dualism

Property dualism describes a nature of positions in the philosophy of mind which throw that, although the world is composed of just one family of substance—the physical kind—there equal two distinct kinds of properties: physical properties as living as mental properties. In other words, it is the impression that non-physical, mental properties such(a) as thoughts, imagination and memories symbolize in, or naturally supervene upon,physical substances namely brains.

Substance dualism, on the other hand, is the concepts that there exist in the universe two fundamentally different kinds of substance: physical matter and non-physical mind or consciousness, and subsequently also two kinds of properties which inhere in those respective substances. Substance dualism is thus more susceptible to the mind–body problem. Both substance and property dualism are opposed to reductive physicalism.

Epiphenomenalism

sensations, volition, ideas, etc., such(a) mental phenomena themselves form nothing further - they are causal dead ends.

The position is credited to English biologist Thomas Huxley Huxley 1874, who analogised mental properties to the whistle on a steam locomotive. The position found favour amongst scientific behaviourists over the next few decades, until behaviourism itself fell to the cognitive revolution in the 1960s. Recently, epiphenomenalism has gained popularity with those struggling to reconcile non-reductive physicalism and mental causation.

In the paper "Epiphenomenal Qualia" and later "What Mary Didn't Know" Frank Jackson portrayed the so-called cognition argument against physicalism. The thought experiment was originally made by Jackson as follows:

Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black and white room via a black and white television monitor. She specializes in the neurophysiology of vision and acquires, permit us suppose, any the physical information there is to obtain approximately what goes on when we see ripe tomatoes, or the sky, and ownership terms like 'red', 'blue', and so on. She discovers, for example, just which wavelength combinations from the sky stimulate the retina, and precisely how this produces via the central nervous system the contraction of the vocal cords and expulsion of air from the lungs that results in the uttering of the sentence 'The sky is blue'. [...] What will happen when Mary is released from her black and white room or is given a color television monitor? Will she learn anything or not?

Jackson continued:

It seems just obvious that she will learn something about the world and our visual experience of it. But then this is the inescapable that her previous cognition was incomplete. But she had any the physical information. Ergo there is more to have than that, and Physicalism is false.