Exceptionalism, to what extent?
Here is something that I have been thinking about, for the chapter I am revising at the moment:
In my thesis, I focus on these two formulations of the conceivability argument:
The Two-Dimensional Argument against physicalism
(1): P&~Q is conceivable
(CP): If S is (ideally) conceivable, then S is primarily possible
(2): If P&~Q is conceivable, P&~Q is primarily possible
(3): If P&~Q is primarily possible, either P&~Q is secondarily possible or Russellian (type-F) monism is true
(4): If P&~Q is secondarily possible, Physicalism is false
(5) Either Physicalism is false or Russellian (type-F) monism is true
The Two-Dimensional Argument against Type-identities
(1) The identity-statement ‘Pain=C-fibre firing’ is a posteriori
(2) If an identity statement A=B is a posteriori, then the terms A and B have different primary intensions (DPIM)
(3) Therefore , ‘pain’ and ‘C-fibre firing’ have different primary intensions
(4) The primary and secondary intension of ‘pain’ coincide
(5) The primary and secondary intension of ‘C-fibre firing’ coincide
(6) Therefore, ‘pain’ and ‘C-fibre firing’ have different secondary intensions
(7) If ‘pain’ and ‘C-fibre firing’ have different secondary intensions, then ‘pain=C-fibre firing’ is false.
(8) ‘Pain=C-fibre firing’ is false.
My critique focuses on premises CP (conceivability-possibility link) and DPIM (distinct primary intension model), as a good type-B materialist would have it.
In particular, I defend the following view concerning concepts:
(Non-reductive Ascriptivism) For any concept C, there is an application conditional like this: (AC): ‘If x is F, then x falls under C’, where for most concepts C from level n, feature F is described using same-level concepts.
If this view is correct, then it follows that sentences such as 'If microphysical truths are so and so, then water is H20' will not be a priori true, since we will not be able to deduce truths involving macroscopic concepts such as WATER from lower-level truths merely a priori. Then, we can use such conditional as a counterexample to CP, since it will plausibly be an a posteriori but 1-necessary conditional (ignoring some complications involving 'totalities' and 'indexicalities'. See Chalmers & Jackson "Conceptual Analysis and Reductive Explanation", Philosophical Review 2001, for further discussion).
But on my view there is an asymmetry concerning CP and DPIM: notice that the view I call non-reductive ascriptivism does not entail that DPIM is false (at least, when we focus on standard sentences not involving phenomenal concepts). For standard cases of a posteriori necessities still seem to fit DPIM. Consider the following examples: 'Water = H20'; 'Heat= molecular motion'. For these cases of a posteriori necessities, the different terms in each identity seem to be associated with different primary intensions.
Then, it seems that a strategy against conceivability arguments that relies upon non-reductive ascriptivism exclusively, still has to face the challenge posed by the two-dimensional argument against identity theses above. True, it is widely accepted that physicalism is not committed to an identity thesis. Still, such argument can prove to be lethal for many positive views about consciousness that want to identify phenomenal properties with some sort of complex physical-functional properties.
On my view, such theorists should appeal to the so-called phenomenal concept strategy, or exceptionalist strategy, according to which DPIM is correct in general but not when it comes to phenomenal concepts.
This sort of strategy (non-reductive ascriptivism plus phenomenal concept strategy) is what I call a mixed strategy against conceivability arguments. Notice that, according to this view, CP is incorrect in general, whereas DPIM is incorrect only when it comes to phenomenal concepts. In my thesis, I try to defend something like that.
Any thoughts are more than welcome!