Abstract

Unconditionals are syntactic conditionals whose affirmation affirms their consequent, unconditionally. Prominent instances were addressed by J.L. Austin ('There are biscuits if you want some') and Nelson Goodman (even-if 'semifactuals'). Their detailed features are explained in a Decision-Theoretic Semantics (DTS) which extends, by certainty and relevance conditions, the "CCCP" conditional probability construal of conditionals due to Ernest Adams and others. The construal of assertions of conditionals as conditional acts, defended by Keith DeRose and Richard Grandy in 1999 against objections arising from Austin's unconditionals, is shown to be incompatible with any known version of CCCP. However, an ad-hoc decision-theoretic construal of their proposal is seen to work for Austin's unconditionals, albeit for these only. The DTS account of unconditionals hinges on stochastic independence or irrelevance conditions. For Austin's variant, it also involves changes in the expectations of non-indicator random variables, i.e. properly valuational relevance relations. The widely assumed speaker's knowledge presumption for assertion in general is reconstrued non-transcendently as a proposal to update to ostensible common certainty. This imperative replaces the factive 'T-axiom', KA-> A, of modal logical explications of knowledge to yield an doxastically imperatival, but evidence-sensitive theory of assertoric truth claims. On such a basis, Max Black's and G.E. Moore's ostensibilist account of assertors representing themselves as knowing is defended against Tim Williamson's 1996 and Igor Douven's 2006 respective deontic proposals for a knowledge or rational credibility requirement. Moreover, ostensibly unconditional, unhedged assertion is reconciled with a reality of dimly perceived potential defeaters on recognizing it to be a tacit semifactual, if need be.