Like coastal cities in the third millennium, important areas of human discourse seem threatened by the rise of modern science. The problem isn't new, of course, or wholly unwelcome. The tide of naturalism has been rising since the seventeenth century, and the rise owes more to clarity than to pollution in the intellectual atmosphere. All the same, the regions under threat are some of the most central in human life -the four Ms, for example: Morality, Modality, Meaning and the Mental. Some of the key issues in contemporary metaphysics concern the place and fate of such concepts in a naturalistic world view.