My research concerns our attitudes: beliefs, desires, hopes, fears, regrets, and many others. I'm particularly interested in their conceptual structure, and especially in generalizations that divide the attitudes into interesting and illuminating sub-classes, and when they're rational. I'm also interested in language, particularly how we talk about the attitudes and express them; much of my work overlaps with linguistic semantics. Finally, I am interested in reasoning to improve our beliefs, and I've argued that we can even reason to the other attitudes I mentioned. Apart from my main research interests, I have a serious ongoing interest in Plato and other ancient Greek philosophers.