"Synonymity" has been a major topic in philosophy since the publication of Rudolf Carnap's Meaning and Necessity in 1947, though it was discussed earlier in the writings of W. V. Quine and C. I. Lewis. After Quine and Morton White launched their attacks on the tenability of the analytic-synthetic distinction, around 1950, the two topics became closely linked.

Synonymity and the Analytic-Synthetic Distinction

Analytic statements, in Quine's account, fall into two classes. Those of the first class, exemplified by (1), are logically true.

(1) No unmarried man is married.

Quine has no objection to the notion of analytic truth as used here, for he has what he regards as an acceptable account of the notion of logical truth in terms of which the notion of analytic truth is partially explicated. "The relevant feature of this example is that it not merely is true as it stands, but remains true under any and...