Phyicalist models of the mind
Over the years, many people have tried to explain how the mind works and how mind and brain relate and most of them assume that physicalism is true. There are a number of books, and parts of books, which give good overviews of them such as:[1][2][3].
All of them hit a problem when they consider consciousness, the fact that there is “something it is like” to be a human. No matter how well we model the brain, the fact remains that we are no nearer to explaining consciousness is or how it arises. As Levine states, an explanatory gap [4] stubbornly remains between consciousness which we know exists by direct experience and descriptions of brain or mind.
Researchers respond to that in different ways ranging from saying that consciousness is a mystery which we can never solve to a complete denial that there is a problem at all, even to the extent of denying that consciousness exists. Christof Koch compares this latter view, eliminativism, as akin to Cotard's syndrome, a psychiatric condition in which patients deny being alive! [5]
Intuitively the mind and the brain seem like very different entities. What does the feeling of pain or joy or the feelings associated with seeing a work of art have in common with the physical workings of a brain? No link, other than some unexplained correlations, have so far been found.
On the basis of the physicalist presupposition, it is not possible to find an explanation for consciousness because Physicalism has implicitly ruled it out.
Those who take the view that there is nothing more to the mind than the material it is made of tend to reject quite vehemently any suggestion that there is more to minds than this, eg. [1].
According to Dennis Dennett, “Accepting Dualism is giving up”.[9]p 91. Hardly a scientific approach!
The majority of models of brain and mind start from what can be observed from the outside, or “third party” observations. These, in contrast to phenomenal experience, can be measured and are publicly observable, therefore amenable to the methods of science. Some theories of this type aim to solve the problem of phenomenal consciousness by this route, others ignore phenomenal consciousness altogether and yet others would deny that there is a problem at all.
Essentially physicalism tries to reverse engineer the mind on the basis of its outputs in response to different inputs. Consciousness is ignored or side-stepped.
Flavours of physicalism
There are many physicalist theories of the mind such as:
Philosophical Behaviourism ([10] chapter 2)
Psychological Behaviourism ([10] chapter 2)
Identity Theory ([1], [10] chapter 3)
Functionalism ([10] chapter 4)
Representational Theory of Mind (RTM) ([3] [11])
Computational Theory of Mind (CTM)
Integrated Information Theory (IIT) (eg. [12])
Eliminativism and Fictionalism ([10] chapter 5)
Inadequacy of physicalism
There are several well known arguments against physicalism although it seems to me that the inadequacy of physicalism is almost self-evident. David Papineau [1] is someone who strongly disagrees.
Jackson’s knowledge argument ([13], [14], [1] chapter 2, [10] chapter 12)
Levine’s Explanatory Gap ( [15] [1] chapter 5 [10] chapter 12)
Kripke’s Modal argument (eg. [1] chapter 3)
[1] David Papineau, “Thinking about Consciousness”, Clarendon Press, 2002,ISBN 0-19-927115-1
[2] Susan Blackmore,”Consciousness, an introduction”, Hodder Education, 2003, ISBN 978-1-444-104-875
[3] John Heil, “Philosophy of Mind”, Routledge, 1998,ISBN 0-415-13060-3
[4] Jospeh Levine, “Materialism and Qualia: The explanatory gap”, Pacific Philosophical Quarterly, 64:354-61, 1983
[5] Koch, Christof (2019). The Feeling of Life Itself: Why Consciousness is Everywhere But Can't be Computed. MIT Press. p. 2.
[9] D. Dennett, “Consciousness Explained”, Boston and London, Little, Brown and Co., 1991
[10] Ian Ravenscroft,”Philosophy of mind, a beginner's guide”, Oxford University Press, 2005,ISBN 978 0-19-925254-1
[11] Fodor, J.A., 1975. The Language of Thought, New York: Crowell.
[12] Oizumi M, Albantakis L, Tononi G (2014) From the Phenomenology to the Mechanisms of Consciousness: Integrated Information Theory 3.0. PLoS Comput Biol 10(5): e1003588. doi:10.1371/journal.pcbi.1003588
[13] F. Jackson, “Epiphenomenal qualia”, Philosophical Quarterly 32: 127-36, 1982
[14] F. Jackson, “What Mary didn't know”, Journal of Philosophy 83:291-295, 1986
[15] Jospeh Levine, “Materialism and Qualia: The explanatory gap”, Pacific Philosophical Quarterly, 64:354-61, 1983