I work in the overlapping fields of metaphysics, epistemology, logic, and the philosophy of language/mind. I am currently pursuing three goals: to articulate a theory of vagueness by developing a logical semantics according to which some sentences are neither true nor false; to explain the ways in which logic is normatively related to thought; and to prove that any modal argument which tries to establish the existence of an intelligent designer from the fact of fine-tuning fails, because no explanation of fine-tuning, theistic or otherwise, is required. Let me say more about each of these.

First, vague predicates threaten \textit{bivalence}, which is the thesis that any statement (proposition, sentence, or assertion) is either true or false. For example, if Byron is a borderline case of baldness, then it is neither correct nor incorrect to call him bald, and so the assertion that he is bald is neither true nor false. Timothy Williamson argues that denying bivalence is self-contradictory. I argue that Williamson's two proofs beg the question against the anti-bivalentist, because he mischaracterizes the anti-bivalentist position and assumes bivalence in his two proofs. Bivalence can be denied, I argue, only by recognizing that it involves two extensions of classical negation. I also argue that by extending classical logic and introducing a borderline predicate I can explain first-order vagueness, which is characterized by predicates that yield borderline statements, such as ``Byron is bald." My account can also explain higher-order vagueness, where it is indeterminate whether, for example, Byron is a borderline case of baldness.

Second, I argue that any rational creature must have certain logical abilities. My position is opposed to naturalized epistemology, which holds that it is a purely empirical question which logical abilities a rational creature has. I argue that any creature meeting certain necessary conditions on rationality must have certain specific logical concepts and be able to use them in certain specific ways. For example, I argue that any creature able to grasp theories must have a concept of conjunction subject to the usual introduction and elimination rules. I deal in the same way with disjunction, conditionality and negation. Finally, I demonstrate how my arguments help define a notion of logical transparency which would be helpful in contexts of radical translation (e.g Donald Davidson) and epistemic logic, in which such a concept of logical transparency is often invoked.

Third, the argument from fine-tuning is supposed to prove the existence of an intelligent designer from the fact that the evolution of carbon-based life requires the laws of physics and the boundary conditions of the universe to be more or less as they are. It is for this reason that the universe is said to be ``fine-tuned" for life. The fine-tuning argument presupposes that the laws of physics or the boundary conditions of the universe could have been other than they actually are. But I argue that the modality being invoked is either logical possibility (and so the physical constants could take any real number as their value) or physical possibility (in other words, consistency with the laws of physics and physical constants as we find them). If it is logical possibility, then the fine-tuning argument proves too much; it proves that the universe is impossible, not simply improbable. On the other hand, if it is physical possibility, then there is no non-arbitrary way for physics to determine which set of boundary conditions are more probable than others, for such speculation goes beyond the scope of physics. I conclude that, even granting fine-tuning, it does not follow that the universe is improbable, and thus no explanation of fine-tuning, theistic or otherwise, is required.