 Guy Longworth (2019) has detailed how much Austin owed to Cook Wilson on knowledge (see Urmson (1988) for a discussion in relation to Prichard): Austin held the ‘knowledge first’ view and, concomitantly, rejected the possibility of a theory of knowledge (Austin 1962, 124), he viewed knowledge as akin to proof, thus as being different in kind from belief on accumulation of evidence (see Austin (1962, 115) &amp; (1979, 99)). But Austin dropped the ‘accretion’ in ‘Other Minds’ as he shifted the analysis of the claim that ‘If I know, I can’t be wrong’ (SI (69) &amp; Prichard (1950, 88)) to that of ‘I know that p’ as providing a form of warrant, one’s authority for saying that p (Austin 1979, 99–100). Krista Lawlor (2013) recently suggested that Austin introduced here the speech act of ‘assurance’. (Although it has been claimed that the idea of ‘performatives’ originates in an exchange of letters on promises with Prichard (Warnock 1963, 347), that dimension remained unexplored in Oxford Realism before Austin, who was consciously moving away here from strict focus on ‘statements’.) 