Brown, C. D., & Papineau, D. (2024). Illusionism and a posteriori physicalism; No fact of the matter Journal of Consciousness Studies
[Abstract]Illusionists and a posteriori physicalists agree entirely on the metaphysical nature of reality—that all concrete entities are composed of fundamental physical entities. Despite this basic agreement on metaphysics, illusionists hold that phenomenal consciousness does not exist, whereas a posteriori physicalists hold that it does. One explanation of this disagreement would be that either the illusionists have too demanding a view about what consciousness requires, or the a posteriori physicalists have too tolerant a view. However, we will argue that this divergence of opinion is merely an upshot of the semantic indeterminacy of the term ‘conscious’ and its cognates. We shall back up this diagnosis by showing how semantic indeterminacy of the kind in question is a pervasive feature of language. By illustrating this pattern with a range of historical examples, we shall show how the dispute between the illusionists and their a posteriori physicality opponents is one instance of a common kind of terminological imprecision. The disagreement between the illusionists and the a posteriori physicalists is thus not substantial. In effect, the two sides differ only about how to make an indeterminate term precise. The moral is that they should stop looking for arguments designed to settle the dispute in their favour.
[Citing Place (1956)]  
Citing Place (1956) in context (citations start with an asterisk *):
Section 6 Objections
Subsection 4. The Phenomenological Fallacy
* A similar point applies to the apparent involvement of worldly properties like yellowness and squareness in certain conscious states. As U. T. Place originally observed (1956), it is very natural to think that sensory experiences literally incorporate the worldly properties they respond to, and thence to conclude that experiences must be non-physical, given that physical brain processes involved in seeing yellowness and squareness are not themselves yellow or square. (Place called this “the phenomenological fallacy”.)
Illusionists often appeal to this line of thought in defence of their position. They argue that the intuitive involvement of worldly properties in conscious experiences show that our concept of consciousness rules out physical realization. Fn 9 For instance, Dennett 2016, pg. 70 suggests that the “seeds of illusionism can already be discerned in U.T. Place’s pioneering article, ‘Is Consciousness a Brain Process?’ (1956). Place was so bold as to identify the denial of illusionism as a fallacy, the phenomenological fallacy.” But our response to this objection is the same as to the last one. It might be natural to think that conscious experiences incorporate worldly properties, and the incompatibility with physicalism might immediately follow. But this does not establish that ‘conscious’ semantically imposes requirements incompatible with physicalism, any more than the naturalness of thinking that stars are fixed in celestial spheres means that this assumption is semantically required by the term ‘star’.