Philosophy is linguistic' may mean at least six different things. (1) The study of language is a useful philosophical tool. (2) It is the only philosophical tool. (3) Language is the only subject matter of philosophy. (4) Necessary truths are established by linguistic convention. (5) Man is fundamentally a language using animal. (6) Everyday language has a status of privilege over technical and formal systems. These six propositions are independent of each other. (1) has been accepted in practice by every philosopher since Plato. Concerning the other five, philosophers have been and are divided, including philosophers within the analytic tradition. In my own opinion (1) and (5) are true, and the other four false. But I do not argue for this sweeping generalization anywhere in the present book.