My main research interests lie in philosophy of psychology and philosophy of mind. I am particularly interested in the nature of belief, the architecture of the mind, and phenomenal consciousness.

My early research was on the nature of belief and belief-desire explanation. Building on ideas by Ronald de Sousa, Daniel Dennett, and Jonathan Cohen, I argued that we use the term ‘belief’ for two different types of state, which belong to two different levels of mentality and figure in different types of explanation. This work culminated in a monograph, Mind and Supermind (2004), which set out the two-level framework and explored its implications for issues in philosophy of mind. A subtheme of this work was the threat of eliminativism about belief — a threat which, I argued, diminishes considerably if we distinguish different levels of belief.

The two-level framework I developed in this work has strong connections with dual-process and dual-system theories in cognitive and social psychology, and I went on to look at these connections and explore the philosophical implications of psychological theories of mental duality. In 2006 I initiated the first-ever major conference dedicated specifically to dual-process theories, which I co-organized with Professor Jonathan Evans of the University of Plymouth. The event brought together leading dual-process theorists from a variety of disciplines for a three-day meeting in Cambridge, UK. Jonathan and I later co-edited a collection of papers derived from the conference (In Two Minds: Dual Processes and Beyond, 2009), which represents the state of the art in the field. The volume also contains a long survey chapter co-authored by Jonathan and myself and my own paper ‘Systems and levels’ which seeks to integrate dual-process theory with a two-level framework.

I continue to think about mental duality and mental architecture and am currently exploring the implications of a two-level conception of the mind for our understanding of various psychopathologies. I am particularly interested in psychotic delusions and their connections with non-pathological delusions and with forms of religious belief. This work will culminate in a book on the nature and pathology of conscious thought.

Another of my research interests is consciousness, where I identify myself as a type-A materialist, who is eliminativist about traditional concepts of qualia and phenomenality. I have published a counter-blast to the zombie argument (‘The anti-zombie argument’), which shows how the tools of the zombists can be turned against them and used to argue for materialism, and I have recently finished a new paper querying the coherence of the weak conception of qualia often employed in debates about the metaphysics of consciousness. I have also written a textbook on consciousness, which is used for an Open University course.

In addition, I have research interests in the areas of philosophy of action, epistemology, philosophy of language, and philosophical logic, and have published papers on semantics of indirect discourse, doxastic voluntarism, and conversational implicature (with Maria Kasmirli).

As well two single-authored books, I have co-edited a volume of research papers in philosophy of action (New Waves in Philosophy of Action, co-edited with Jesus Aguilar and Andrei Buckareff, and am currently completing editorial work on two volumes in the ‘Cambridge Handbooks’ series, in collaboration with William Ramsey of the University of Nevada (The Cambridge Handbook of Artificial Intelligence and The Cambridge Handbook of Cognitive Science).

I am a strong believer in the importance of interdisciplinary collaboration. At Sheffield I was also closely involved in the work of the Hang Seng Centre for Cognitive Studies and was co-editor of the interdisciplinary web journal Connexions. More recently, I was for several years as Director of The Open University’s Mind, Meaning, and Rationality Research Group . I am currently an Adjunct Professor with the Brain and Mind Program at the University of Crete, which acts as focus for a vigorous community of researchers in cognitive science and AI. I am also co-owner of a weblog on evolutionary topics, called ‘Evolving Ideas’.