 For book length defenses of inferentialism, see Brandom (1994) and Brandom (2000). Important precursors include Wittgenstein (1953) and Sellars (1968); see also the entries on  Ludwig Wittgenstein  and  Wilfrid Sellars.  For a classic objection to inferentialism, see Prior (1960). For a discussion of a prominent approach within the inferentialist tradition, see the entry on  proof-theoretic semantics.