J. L. Austin
John Langshaw "J. L." Austin (26 March 1911 – 8 February 1960) was a British philosopher of language and leading proponent of ordinary language philosophy, perhaps best known for developing the theory of speech acts.
Prior to Austin, the attention of linguistic and analytic philosophers had been directed almost exclusively to statements, assertions, and propositions — to linguistic acts that (at least in theory) have truth-value. This led to problems when analyzing certain types of statements, for example in determining the truth conditions for such statements as "I promise to do so-and-so."