I am a philosophical generalist with a home base in the metaphysics of mind. Two questions that occupy a lot of my time are:

  • What is the nature of conscious experience?

  • What makes it the case that a representation (linguistic, mental, or other) has the meaning that it does?

These topics have led me to investigate the metaphysical status of consciousness, spatial concepts and spatial vision, twin-earth scenarios, the physicalim-dualism debate, the formulation of physicalism, fundamentality, grounding, modality, a priori justification, the knowledge argument, reference for mathematical terms, metaphysical methodology, concepts, understanding, as well as analog and iconic representation.

A fuller description of my research profile can be found in this research statement, which traces three recurring themes through my work. Those themes are:

  1. Concept Mastery: A thinker has mastery of a concept when they fully understand that concept. Burge(1979)’s arthritis patient lacks mastery of the concept ARTHRITIS; his doctor has it. Concept mastery is a useful notion in numerous areas of philosophical inquiry. I believe that both the nature and importance of the phenomenon have been misunderstood; it should not be labeled as “mere social deference” and ignored as a deviant phenomenon.

  2. Metaphysical Rationalism: optimism about the revelatory power of a priori reflection in metaphysical inquiry.

  3. Semantic Externalism: the nature of a representation is determined by factors external to the representational system.

Some published papers:

 An edited volume I am preparing:

  • Grounding and Consciousness, Oxford University Press, forthcoming.

Some unpublished papers:

Comments are welcome. Some of these are currently under review.

Toward a Theory of Concept Mastery - A thinker can possess, and think thoughts with, concepts he or she does not fully understand. This paper investigates the question "Under what conditions does a thinker fully understand, or have mastery of, a concept?" I lay out a gauntlet of considerations, problems, and desiderata with which any theory of concept mastery must cope. I use these considerations to argue against three views of concept mastery, according to which mastery is a matter of holding certain beliefs, being disposed to make certain inferences, or having certain intuitions. None of these attitudes is either necessary or sufficient for mastery. I propose and respond to objections to my own "recognition view" of the conditions under which a thinker has mastery of a concept.

The Meta-Semantic Dilemma for Two-Dimensional Semantics - Two-Dimensional Semantics, as developed in the work of David Chalmers and Frank Jackson (Chalmers [2006b,a], Jackson [1998, 2010]) founders on a dilemma. The theory claims that, when evaluated at the actual world, primary/A-intensions coincide with secondary/C-intensions (the coincidence thesis). It also claims that primary/A-intensions are narrow contents (the narrow content thesis). Both claims cannot be true. If primary/A-intensions coincide with secondary/C-intensions, then primary/A-intensions must be meta-linguistic. If they are meta-linguistic, they are not fit to play the role of narrow content. Two-Dimensional Semanticists must give up one of these two foundational theses.

Existence and the Existential Quantifier - I draw a distinction between the existential quantifier and the symbol '∃' used to express it, on the one hand, and existence and 'exists', on the other. I argue that some popular arguments in metaphysics, including arguments against vague existence and arguments against deflationary meta-ontology (which views ontological disputes as lacking substance), are guilty of fudging this distinction. I draw some lessons for metaphysical debate about existence and highlight some heretofore ignored and attractive positions in logical space. The most important lesson is: in formal metaphysics, don't confuse the things themselves with the formal tools used to model them.

Against Old Facts Under New Modes - Jackson [1982, 1986] envisions a thought experiment involving Mary, a color-deprived neuroscientist raised in a black and white room, who knows all the physical facts. When she emerges from the room and sees a ripe red tomato for the first time, she learns a new fact. Therefore, says the knowledge argument, not all facts are physical facts. The "old fact new mode" view denies that Mary does not know all the facts while in the black and white room. When Mary sees the red tomato, she learns an old fact, a fact she already knew, in a new way. I argue that the old fact new mode view cannot be correct. It is committed to an identity claim between facts that makes it vulnerable to an objection reminiscent of multiple realizability objections against mental-physical identity views in the philosophy of mind.

Fundamentality Physicalism - This essay has three goals. The first is to introduce the notions of fundamentality and metaphysical generation and to argue that physicalism can usefully be conceived of as a thesis about fundamentality. Toward this end, I argue (i) that fundamentality physicalism has advantages over currently popular modal formulations of physicalism and (ii) that fundamentality physicalism is what many who endorse modal formulations of physicalism had in mind all along. The second goal is to explore several other potential formulations of physicalism, including as a thesis about identity, realization, natures, explanation, language, and concepts. The third goal is to contrast fundamentality physicalism with these other theses and offer reasons to prefer fundamentality physicalism over these other formulations.

Going Non-Standard on the Standard Problem - I offer two solutions to the standard problem for coincident objects. Both rely on the notion of metaphysical ground. The first solution argues that despite sharing the same parts, the two objects do not share the same grounds. The second solution argues that the difference between the two coincident objects can be explained using structures of metaphysical dependence. I argue for a form of metaphysical externalism and against a mereological approach to the metaphysics of objects, and argue that the differing formal properties of ground vs. part-hood yield an expansion of explanatory resources when coping with the standard problem.