Non-direct speech acts are contrasted with explicit performatives: non-direct speech acts using explicit performative formulae and non-direct speech acts which cannot possibly use explicit performative formulae are considered. Three descriptive schemes for non-direct speech acts are proposed: one for indirect speech acts (defined as follows: an indirect speech act SA2 is part of a direct speech act SA1 and can be interpreted as the intended one if SA1 thematizes under certain contextual circumstances one of the constitutive presuppositions of the direct performance of SA2), one for implicit speech acts (defined as follows: an implicit speech act SA2 is part of a direct speech act SA1 and can be interpreted as the intended one if the propositional component p of an explicit form of SA2 is a presupposition of SA1 and if p is not questioned by a direct performance of SA1), and one for implicative propositions (comparable to Grice's implicature). Some thoughts about the social function of non-direct speech acts are attached.