Two Dogmas

If there is something about the world that makes 'Vixens are foxes' true, it is not that Vixens are foxes, but that the world allows us to speak that way.

In fact, the only 'fundamental' thing we can say about the world is that it allows us to speak the way we do: and we can know this a priori, because we can know (in the context of speaking to one another) 'we can speak about the world' a priori.

If we try to say anything else, if we propose some other metaphysical fundamental, we are introducing a new constraint. We can do this with respect to more constrained games (for which these constraints might be hinge propositions), but in the most general cases we are caught by the 'as though' problem: that no philosophical importance can be attached to distinguishing between, for example, 'There are real physical objects in the world' and 'we can talk as though there are real physical objects in the world'. 'We can talk' and 'We can talk as though we can talk' is the only general circumstance in which the metaphysical implication is direct - the second statement is just a repetition of the first.