• Metaphysics
• Political Philosophy
• Aesthetics

I am primarily interested in metaphysics, political philosophy, and aesthetics.  My book "Negatives Selbstbewusstsein" (2002) reflects upon Kant's theory of self-consciousness, and my book "Das Absolute und das Subjekt" (2008) deals with the tension between metaphysical and postmetaphysical thinking.  I have edited a volume on Spinoza's political philosophy (2006) and, together with the late Ruediger Bubner, the proceedings of the International Hegel-Congress 2005.  Currently, I am working on two major projects:  on a study on the relation between naturalism and humanism, and on a philosophy of music.

• Kant
• Modern Philosophy
• Aesthetics

I work on the history of modern philosophy, especially Kant, and on the history of aesthetics. I have worked on Kant's epistemology and metaphysics, his moral and political theory, and on his aesthetics, and on issues in both epistemology and aesthetics in a wide range of other authors. I am also one of the General Co-Editors of the Cambridge Edition of Kant, for which I translated three volumes of Kant's works.  Thirteen volumes of this edition have been published and two more are in press as of September, 2011; only one remains to be completed. My recent works include the first English translation of an extensive selection of Kant's posthumous Notes and Fragments (2005) in the Cambridge Edition; a survey of Kant, called simply Kant (2006); a Reader's Guide to Kant's Groundwork for the Metaphysics of Morals (2007); and three collections of my essays, Kant's System of Nature and Freedom (2005), Values of Beauty: Historical Essays in Aesthetics (2005), and Knowledge, Reason, and Taste: Kant's Response to Hume (2008). In August, 2011, I completed a three-volume history of modern aesthetics from the eighteenth through the twentieth centuries, entitled The Evolution of Modern Aesthetics: Truth, Feeling, and Play; it will appear soon. My next project will be a book on the impact of Kant's moral philosophy on the subsequent history of philosophy, as part of a series on The Legacy of Kant that I am editing for Oxford University Press, which will also include volumes by Michael Friedman, Sebastian Gardner, Howard Williams, and Paul Frank.

At the mid- and graduate level, I teach all areas of Kant on a regular rotation, I teach a rotation of courses on eighteenth-, nineteenth-. and twentieth-century aesthetics.  I also teach eighteenth-century British moral philosophy.  At the introductory level I teach aesthetics and the history of modern philosophy.  I am occasionally able to offer seminars on the reception of various areas of Kant's philosophy.

My research focuses on thoughts and utterances that don’t fit standard propositional models. I am especially interested in cognitive "perspectives", in which one thought structures our overall understanding of a topic in a way that's similar to the way a concept like duck or rabbit can structure our perceptual experience. I've thought most about perspectives in our understanding of metaphor and fiction, but I'm also working on their role in emotions and the self. In addition, I am interested in the thought of non-human animals, in thought that takes place in maps rather than sentences, and in sarcasm and slurs.