In this book Gregory Browne rejects the views of David Hume and the Logical Positivists, and argues that there are necessary factual truths, which include a wide range of truths from many fields of knowledge. Browne argues for the necessity of Newton’s Laws and truths about natural kinds, and for the factuality of definitional truths and truths of logic and mathematics. Browne synthesizes the work of Kripke, Putnam, Quine and others, but goes beyond the usual discussions of the meanings and definitions of terms to discuss the references of various kinds of terms, and specifically to develop a theory of kinds, distinguishing ‘Deep Kinds’ (roughly, natural kinds) and ‘Shallow Kinds’ (e.g., triangles, bachelors). His theory of Deep Kinds does not accept all of the assumptions commonly associated wtih a theory of natural kinds.