For Logical Positivists, such as A.J.Ayer, the only statements that can be verified are those that are analytic. According to Ayer, they cannot be confirmed or refuted by facts of experience, and "do not make any assertion about the empirical world, but simply record our determination to use symbols in a certain way."
In From a Logical Point of View, Willard van orman Quine rejects Kant's distinction of analytic and synthetic. He divides analytic statements into two classes: The first is logically true.
(1) No unmarried man is married.
For Quine this statement remains true for all interpretations of man and married. It only depends of the logical particle "un".
A second class of analytic statements, according to Quine would be:
(2) No bachelor is married.
The characteristic of the latter statement would be that it could be reduced to the first by the substitution of "unmarried man" for its (cognitive) synonym, "bachelor". However, for Quine the notion of "synonym" is as problematic as the notion of "analytic" Quine considers synonymity to be grounded in usage. Accordingly, it must be synthetic.
(Although I would have thought, that in Kant's terminology this would have meant "a posteriori" instead of "a priori and synthetic", and that we would here be speaking of "a posteriori analytic", a state that I presume neither Kant nor Quine would find acceptable) (Or else Quine has perhaps accepted the analytic / synthetic distinction after all)