The fourth volume of Boston Studies in the Philosophy of Science consists mainly of papers which were contributed to our Colloquium during the past few years. The volume represents a wide range of interests in contem- porary philosophy of science: issues in the philosophy of mind and of language, the neurophysiology of perceptual and linguistic behavior, philosophy of history and of the social sciences, and studies in the fun- damental categories and methods of philosophy and the inter-relation- ships of the sciences with ethics and metaphysics. Papers on the logic and methods of the natural...