If there exist such things as the things we mean, then those things are also the things we believe, and the things in terms of which we must understand all semantic notions. If such entities as the things we mean and believe exist, an account of their nature must be the most foundational concern in the theory of linguistic and mental representation.

Schiffer argues that there are such things as the things we mean and believe. They are what he calls pleonastic propositions, and he provides an account of what they are in themselves and of their place in nature, language and thought.

After developing the theory of pleonastic propositions, Schiffer uses it to provide accounts of (among other things) linguistic meaning and knowledge of meaning, the relation between intentional and non-intentional facts, vagueness and indeterminacy, moral discourse, conditionals, and the role of propositional content in information acquisition and explanation.

This radical new treatment of meaning will command the attention of everyone who works on fundamental questions about language, and will attract much interest from other areas of philosophy.