 The category for sentences that are analytic and yet represent a posteriori knowledge deserves discussion. The empirical study of the use of language within language-using communities by field linguists involves establishing the grammar and the vocabulary employed within each such community. Their empirical research yields theories of the languages, \(\mathbf{L}\), used in those communities and affords a basis for distinguishing between which sentences are analytic-in-\(\mathbf{L}\) and which are synthetic-in-\(\mathbf{L}\). The kind of knowledge they acquire about specific sentences based on empirical procedures thus assumes the form, “Sentence \(S\) is analytic-in-\(\mathbf{L}\)”, when that is true of sentence \(S\), which is a posteriori.