D. Gene Witmer

In his Consciousness and Fundamental Reality (2017) Philip Goff defends his anti-physicalist argument against what he calls the "Dual Carving" objection—the idea that two representations of the very same fact could both be conceptually independent and "transparent," that is, revealing of the essences of the entities in question. His defense invokes a thesis he calls "Minimal Rationalism." I explore exactly how Minimal Rationalism is supposed to turn aside the objection and argue that the formulation of Minimal Rationalism on offer is ambiguous between stronger and weaker readings. Goff needs the stronger reading to use it in defense of his argument, but only the weaker reading is warranted by the considerations he brings to bear in favor of his rationalism. His minimal rationalism is, in sum, insufficiently minimal. The upshot is not only that Goff is deprived of a way of turning back an important objection to his case against physicalism; we also gain a better sense of what kind of rationalist thesis is properly invoked in metaphysics.

What has become known asthe blockers problemis an alleged difficulty facing attempts to formulate physicalism as a supervenience thesis. A blocker is an entity, itself contrary to physicalism, with the power to disrupt an otherwise necessary connection between physical and nonphysical conditions. I argue that there is no distinct blockers problem. Insofar as a problem can be identified, it turns out to be just a rather baroque version of a distinct and familiar objection to supervenience formulations and to be of no independent interest. Work on the formulation of physicalism can thus proceed without worrying about blockers.

In his book Intuition, Elijah Chudnoff develops an account of how we might, by having intuitions, be made aware of abstract objects. While the conditions under which we enjoy such awareness are, on his account, happily free of objectionable metaphysics or dubious mechanisms, it is not clear that the conditions bear the epistemic weight they need to carry. To flesh out this worry, I develop an example that is parallel in all relevant respects to cases of intuitive awareness as described by Chudnoff but in which the subject lacks awareness. This paper is a descendant of remarks delivered at the 2014 conference of the Florida Philosophical Association during a book symposium on Elijah Chudnoff’s Intuition.

Contemporary materialism labors under two serious difficulties: the problem of formulation and the problem of justification. It remains unclear just what physicalism says or why one should believe it. I propose an explicit formulation and provide a sustained argument for that specific thesis. The overall thesis I defend may be roughly stated thus: every nonphysical particular and lawful fact in the actual world is to be explained by reference to the purely physical in such a way as to imply that they are nothing over and above the physical facts, where the purely physical facts include the particular physical facts, the laws of physics, and the completeness of physics. This explanatory claim implies two dialectically key theses which may be roughly expressed as the following. First, any possible world physically indiscernible from the actual one which abides by the laws of physics is indiscernible from the actual one in all respects. Second, any actual law of nature is entailed by the laws of physics, their completeness, and actual particular matters of physical fact. This is a very strict sort of physicalism, one that probably deserves the name "reductionism." ;The core argument turns on the notion of a physically detectable property, that is, a property such that whether it is instantiated can make a difference to physical effects, where this "making a difference" is a causal notion. Given the completeness of physics--the claim, roughly, that every physical event has a sufficient physical cause--all physically detectable properties are plausibly derivative on purely physical properties and laws in such a way as to imply the physicalist thesis described above. I argue that being physically detectable in the relevant way is linked to empirical knowability so that any property instance we could be justified in positing is physically detectable and hence swept up in these considerations. The detectability considerations allied with the completeness of physics provides both the supervenience thesis about particular facts and the law entailment thesis. Together, these make the overarching explanatory claim--that the nonphysical realm is nothing over and above the physical--extremely plausible

Recent work by Jaegwon Kim and others suggest that functionalism leaves mental properties causally inefficacious in some sense. I examine three lines of argument for this conclusion. The first appeals to Occam's Razor; the second appeals to a ban on overdetermination; and the third charges that the kind of response I favor to these arguments forces me to give up "the homogeneity of mental and physical causation". I show how each argument fails. While I concede that a positive theory of mental causation is desirable, there is no reason to think that functionalism renders such a theory unattainable

Charles Siewert has given us an ingenious thought experiment involving a limited lack of conscious experience. The possibility of the described case is incompatible with a number of popular theories of consciousness. Siewert acknowledges, however, that this possibility is not a direct threat to "hidden feature" theories. I aim to do two things: first, strengthen his defense of the claim that the case is genuinely possible by considering and rejecting some further attempts to explain away our temptation to believe it possible; and second, to explore how a hidden feature approach could be developed and made plausible

The manifestability argument presented by Papineau and Loewer turns on the premise that nonphysical properties are capable of making a difference to physical conditions. From this and the completeness of physics a strenuous supervenience conclusion is supposed to follow. I argue that the plausible version of this premise implies a weaker supervenience thesis only, one that is too weak to be of any use for a physicalist. There is a more contentious premise one might use to deduce the needed conclusion, but that more contentious premise has no empirical support

Physicalists motivate their position by posing a problem for the opposition: given the causal completeness of physics and the impact of the mental (or, more broadly, the seemingly nonphysical) on the physical, antiphysicalism implies that causal overdetermination is rampant. This argument is, however, equivocal in its use of 'physical'. As Scott Sturgeon has recently argued, if 'physical' means that which is the object of physical theory, completeness is plausible, but the further claim that the mental has a causal impact on the physical is no longer so evident. In this paper I assess the damage due to the ambiguity of 'physical' and provide a repair to the overdetermination strategy.

Presidential Address for the 2011 meeting of the Florida Philosophical Association. A somewhat playful but also serious meditation on ways in which the philosophical impulse can be understood as an urge to demystify or render "boring." Topics include psychological peculiarities of philosophers, reflections on methods for teaching students at an introductory level, the contrast between science and philosophy, the sense in which philosophy may or may not begin in "wonder," and why we should value the process of taking the magic out of everything, ending with the declaration that it’s good to make everything boring—at least, in the specific sense here delineated.

What has come to be known as “a priori physicalism” is the thesis, roughly, that the non-physical truths in the actual world can be deduced a priori from a complete physical description of the actual world. To many contemporary philosophers, a priori physicalism seems extremely implausible. In this paper I distinguish two kinds of a priori physicalism. One sort – strict a priori physicalism – I reject as both unmotivated and implausible. The other sort – liberal a priori physicalism – I argue is both motivated and plausible. This variety of a priori physicalism insists that the necessitation of non-physical truths by the physical facts must be underwritten in a certain fashion by a priori knowledge, but the a priori knowledge need not amount to a simple deduction of the non-physical truths from a complete physical description of the world. Further, this sort of liberal a priori physicalism has the advantage that it offers hope for a genuinely satisfying account of how the physical facts manage to necessitate the facts about phenomenal consciousness – thereby in effect solving the “hard problem” of consciousness. The first half of the paper sets out the motivation for liberal a priori physicalism and its superiority to the strict version; the second half presents one strategy available to the liberal a priori physicalist for showing how consciousness can be accommodated in a purely physical world