In this chapter I argue for a key premise in the argument I will present (in chapter 4) for anti-individualism regarding the individuation of speech content, linguistic meaning, and (ultimately) the attitudes. The premise itself asserts the existence of public linguistic norms. As developed in the argument to follow, such norms are normative in that they provide standards for the correct usage and interpretation of lexical items (that is, they provide the semantic standards of these items); and such norms are public, first, in that they derive from the shared, public language that is common property to all members of a speech community, and second, in that participants in speech exchanges – speakers and hearers alike – are positively but defeasibly presumed to be answerable to these norms on each particular speech exchange. In this chapter I will be pursuing the idea that the practice whereby knowledge is spread through a speaker's use of language itself depends on the existence of semantic standards provided by the shared public language. Or rather: such standards are required if this practice is to be, as we take it to be, a pervasive and efficient way to spread very specific pieces of knowledge, under conditions in which speaker and hearer may know nothing about one another's speech and interpretative dispositions beyond what is manifested in the brief speech exchange itself.