Asserting is the act of claiming that something is the case—for instance, that oranges are citruses, or that there is a traffic congestion on Brooklyn Bridge (at some time). We make assertions to share information, coordinate our actions, defend arguments, and communicate our beliefs and desires. Because of its central role in communication, assertion has been investigated in several disciplines. Linguists, philosophers of language, and logicians rely heavily on the notion of assertion in theorizing about meaning, truth and inference. -/- (...) The nature of assertion and its relation to other speech acts and linguistic phenomena (implicatures, presuppositions, etc.) have been subject to much controversy. This entry will situate assertion within speech act theory and pragmatics more generally, and then go on to present the current main accounts of assertion. (shrink)

We show that taking together the principle ‘Ought’ Implies ‘Can’ (OIC) and The Knowledge Norm of Assertion (KNA) leads to a contradiction as long as we assume that there are situations in which we ought to assert what we cannot know. We call this The Paradox of Impossible to Know Assertion (PIKA) and argue that this is a genuine problem. At the end, we point out a generalization of PIKA.

An assertion is a speech act in which something is claimed to hold, e.g. that there are infinitely many prime numbers, or, with respect to some time t, that there is a traffic congestion on Brooklyn Bridge at t, or, of some person x with respect to some time t, that x has a tooth ache at t. The concept of assertion has often occupied a central place in the philosophy of language, since it is often thought that making assertions (...) is the use of language most crucial to linguistic meaning, and since assertions are the natural expressions of cognitive attitudes, and hence of importance for theories of knowledge and belief. (shrink)