 Searle's early work, which did a great deal to establish his reputation, was on speech acts.He attempted to synthesize ideas from many colleaguesincluding J. L. Austin (the "illocutionary act", from "How To Do Things with Words"), Ludwig Wittgenstein and G.C.J.Midgley (the distinction between regulative and constitutive rules)with his own thesis that such acts are constituted by the rules of language.