Why should philosophy be interested in what would seem to be a purely linguistic notion Because especially in the first half of the Twentieth Century many philosophers thought it could perform crucial epistemological work providing an account first of our apparently a priori knowledge of mathematics and then—with a little help from British empiricism—of our understanding of claims about the spatiotemporal world as well Indeed “conceptual analysis” soon came to constitute the very way particularly Anglophone philosophers characterized their work Many additionally thought it would perform the metaphysical work of explaining the truth and necessity of mathematics showing not only how it is we could know about these topics independently of experience but how they could be true in this and all possible worlds This latter ambition was sometimes not distinguished from the former one although it is no longer shared by most philosophers still interested in the analytic Indeed many have wondered how could any sentence be true much less necessary “by virtue of meaning alone” since surely the truth of any sentence depends upon the world being the way the sentence represents it as being Recall that Frege’s ambition was to reduce mathematics to logic by showing how substituting synonyms for synonyms every mathematical truth could be shown to be a logical one He didn’t go on to claim although some later philosophers did that the logical truths themselves were true by virtue of meaning alone Thus “Bachelors are unmarried” might be shown to be analytic by substituting “unmarried males” for “bachelors” and converting it thereby to the logical truth “Unmarried males are unmarried” But what makes this latter true As Devitt 1996 pointed out1 It is true partly in virtue of what it means and partly in virtue of the way the world is in virtue of all unmarrieds being unmarried … Such sentences are true in virtue of meaning given the logical truths 1996 p 22 In view of this point in the remainder of this entry we will focus primarily on the epistemological project