This book is nominally about linguistic representation. But, since it is we who do the representing, it is also about us. And, since it is the universe which we represent, it is also about the universe. In the end, then, this book is about everything, which, since it is a philosophy book, is as it should be. I recognize that it is nowadays unfashionable to write books about every thing. Philosophers of language, it will be said, ought to stick to writing about language; philosophers of science, to writing about science; epis temologists, to writing about knowing; and so on. The real world, however, perversely refuses to carve itself up so neatly, and, although I recognize that the real w,orld is nowadays also unfashionable, in the end I judged that one might get closer to the truth of various matters by going along with it. So I have done so. lt was Wilfrid Sellars who initially convinced me of the virtues of this way of proceeding. At this point one normally says something like The debt that this book owes him is immense. I would say it too, were it not to understate the case, From Wilfrid, I learned to think about things. If the upshot of my thinking tends, as it obviously does, to show a general con silience with the upshot of his, it is primarily because he is so very good at it - and he had a head start.