Attitudes towards physicalism also differ among professionals. In the 2009 PhilPapers survey, 56.5% of
philosophers surveyed subscribed to physicalism and 27.1% of philosophers surveyed rejected
physicalism. 16.4% fell into the "other" category.[51] In the 2020 PhilPapers survey, 51.93% of
philosophers surveyed indicated that they "accept or lean towards" physicalism and 32.08% indicated that
they reject physicalism. 6.23% were "agnostic" or "undecided".[25]
Different solutions have been proposed to the hard problem of consciousness. The sections below
taxonomizes the various responses to the hard problem. The shape of this taxonomy was first introduced
by Chalmers in a 2003 literature review on the topic.[52] The labelling convention of this taxonomy has
been incorporated into the technical vocabulary of analytic philosophy, being used by philosophers such
as Adrian Boutel,[53] Raamy Majeed,[54] Janet Levin,[55] Pete Mandik & Josh Weisberg,[56] Roberto
Pereira,[57] and Helen Yetter-Chappell.[58]
Type-A materialism (also known as reductive materialism or a priori physicalism) is a view characterized
by a commitment to physicalism and a full rejection of the hard problem. By this view, the hard problem
either does not exist or is just another easy problem, because every fact about the mind is a fact about the
performance of various functions or behaviours. So, once all the relevant functions and behaviours have
been accounted for, there will not be any facts left over in need of explanation.[52] Thinkers who
subscribe to type-A materialism include Paul and Patricia Churchland, Daniel Dennett, Keith Frankish,
and Thomas Metzinger.
Some type-A materialists believe in the reality of phenomenal consciousness but believe it is nothing
extra in addition to certain functions or behaviours. This view is sometimes referred to as strong
reductionism.[43][52] Other type-A materialists may reject the existence of phenomenal consciousness
entirely. This view is referred to as eliminative materialism or illusionism.[59][60][61]
Many philosophers have disputed that there is a hard problem of consciousness distinct from what
Chalmers calls the easy problems of consciousness. Some among them, who are sometimes termed strong
reductionists, hold that phenomenal consciousness (i.e., conscious experience) does exist but that it can
be fully understood as reducible to the brain.[43]
Broadly, strong reductionists accept that conscious experience is real but argue it can be fully understood
in functional terms as an emergent property of the material brain.[43] In contrast to weak reductionists
(see above), strong reductionists reject ideas used to support the existence of a hard problem (that the
same functional organization could exist without consciousness, or that a blind person who understood
vision through a textbook would not know everything about sight) as simply mistaken intuitions.[43][52]
A notable family of strong reductionist accounts are the higher-order theories of consciousness.[62][43] In
2005, the philosopher Peter Carruthers wrote about "recognitional concepts of experience", that is, "a
capacity to recognize [a] type of experience when it occurs in one's own mental life," and suggested that
such a capacity could explain phenomenal consciousness without positing qualia.[63] On the higher-order
view, since consciousness is a representation, and representation is fully functionally analyzable, there is
no hard problem of consciousness.[43]
Type-A Materialism
Strong reductionism