Philosophy of language is the reasoned inquiry into the nature, origins, and usage of language. As a topic, the philosophy of language for Analytic Philosophers is concerned with four central problems: the nature of meaning, language use, language cognition, and the relationship between language and reality. For Continental philosophers, however, the philosophy of language tends to be dealt with, not as a separate topic, but as a part of Logic, History or Politics. (See the section "Language and Continental Philosophy" below.)

First, philosophers of language inquire into the nature of meaning, and seek to explain what it means to "mean" something. Topics in that vein include the nature of synonymy, the origins of meaning itself, and how any meaning can ever really be known. Another project under this heading of special interest to analytic philosophers of language is the investigation into the manner in which sentences are composed into a meaningful whole out of the meaning of its parts.