Concepts are customarily regarded as intermediaries between mind and world. They are the basic elements of thoughts and the tools by which one classifies things. Concepts are central to the philosophy of mind, and they are often implicated in theories of meaning. There are also some who think that philosophical method is largely a matter of conceptual analysis. There is considerable consensus on the importance of concepts, and, to a lesser extent, on the roles that concepts play, but beyond that there is rampant disagreement. For example, philosophers disagree about the ontology of concepts, the acquisition of concepts, and the content of concepts. In the twentieth century, psychologists began to weigh into these debates, and since the 1970's, much theorizing about concepts has been informed by interdisciplinary dialogue. This entry surveys dominant theories.

What Are Concepts For?

Within philosophy concepts are most often defined as the elements or...