Research

We argue 'conscious' sometimes functions as a minimal-standard gradable adjective. We relate this to issues concerning the semantics of 'what it's like' expressions and the metaphysics of degrees of consciousness.

I argue that purely structural facts about conscious experiences are objective phenomenal facts. They're objective in that they're understandable from any point of view, and phenomenal in that they partially characterize what it's like to have an experience.

I develop an analysis of what it means for consciousness to come in degrees. I argue that standard objections to degrees of consciousness trade upon confusions about the relationship between degrees, indeterminacy, and multidimensionality.

I argue that the standard framework for modeling mental qualities—where qualities are represented via points in geometric spaces—is structurally inadequate. Then I develop a new mathematical framework—the regional framework—that is more powerful and flexible. The regional framework can capture phenomenal imprecision, disentangles two dimensions of phenomenal similarity, and illustrates how phenomenal qualities are structurally different from perceptible qualities.

I develop and defend the view that experiences might have microphenomenal structures, where the macrophenomenal properties we introspect are realized by non-introspectible microphenomenal properties.

To be conscious—according to a common metaphor—is for "the lights to be on inside." But there are two ways of interpreting this metaphor, which correspond to two senses of 'phenomenal consciousness'. I explain how disentangling these senses clarifies some questions about degrees, dimensions, and determinacy of consciousness.

I explain the relationship between the metaphysical question of whether conscious experiences are continuous and the mathematical concept of a continuous function. Then I argue that introspection leaves open whether conscious experiences are continuous or discrete.

I argue that the most promising direction for the future of consciousness research is to follow a path that recurs across the history of science, where an early focus on "essence questions" ('What is X?') is replaced by a later focus on "structural questions" ('How do we model X?'). I discuss the prospects for investigating the structure of consciousness.

I disentangle two senses of 'phenomenal consciousness' — which I call 'subjectivity' and 'phenomenal character' — and argue that the distinction has wide-ranging implications for questions about the structure of consciousness.

I develop a radical view of phenomenal qualities on which every quality can be modeled as a distribution over a high-dimensional vector space. I explain how the view solves the palette problem, the problem of explaining the qualitative diversity of experiences via a compact range of basic resources.

We develop a systematic framework for theorizing about substrates and consciousness, and disentangle substrate independence from multiple realization and functionalism. A core idea is that substrates are best analyzed as "stuff profiles." We argue that instead of asking whether consciousness is substrate independent, we ought to instead ask which substrates support which experiences.

We argue that no current theory of global states of consciousness can satisfy all the theoretical roles associated with global states. Then we develop a new theory that does so. The basic idea is that global states are "total states of subjectivity."