This book develops in detail the simple idea that assertion is the expression of belief. In it the author puts forward a version of 'probabilistic semantics' which acknowledges that we are not perfectly rational, and which offers a significant advance in generality on theories of meaning couched in terms of truth conditions. It promises to challenge a number of entrenched and widespread views about the relations of language and mind. Part I presents a functionalist account of belief, worked through a modified form of decision theory. In Part II the author generates a theory of meaning in terms of 'assertibility conditions', whereby to know the meaning of an assertion is to know the belief it expresses.
Kwame Anthony Appiah, the president of the PEN American Center, is the author of The Ethics of Identity, Thinking It Through: An Introduction to Contemporary Philosophy, The Honor Code and the prize-winning Cosmopolitanism. Raised in Ghana and educated in England, he has taught philosophy on three continents and is a former professor at Princeton University and currently has a position at NYU.