Classical Theory of Concepts

The classical theory of concepts is the view that, at least for ordinary concepts, a subject who possesses a concept knows the necessary and sufficient conditions for something falling under the concept—that is, the definition of the concept. This entry first introduces the theory, and then discusses two powerful objections to it.

There are now many alternative theories of concepts on offer, but they all are, in some way or another, reactions to “the classical theory of concepts,” or “the definitional view of concepts.” The classical theory has two different aspects, though they are often distinguished insufficiently. First, it is assumed that all concepts (except, perhaps, some specific basic or primitive concepts; see below) have a classical analysis, or a definition, in terms of simpler concepts—a definition that gives necessary and sufficient conditions for falling under the concept, or, in other words, for belonging to its extension. Second, it is presupposed that if a subject has or possesses a concept—grasps it—then he or she must know the relevant definition or correct analysis.

Consider thus the worn out example, bachelor (italicized expressions are here used to designate concepts that are expressed by the corresponding words and phrases; the latter are mentioned by putting them in quotes; e.g., “bachelor”). Now, according to the traditional view, bachelor is constituted by the more primitive concepts unmarried and man; thus, bachelor can be defined with the latter, or, those concepts provide its analysis. Hence, it is necessary and sufficient for something to fall under the concept bachelor to be unmarried and a man. Moreover, anyone who possesses the concept bachelor must know this. Or to change the example, presumably the concept vixen can be defined in terms of the concepts female and fox and anyone who has the concept vixen must know that this is the case.

In accordance with such suggestive paradigms, it has been thought that virtually all concepts have a definition in an analogous way. For example, tiger might get analyzed along the lines of a large, carnivorous, quadrupedal feline, tawny yellow in color with blackish transverse stripes and white belly; consequently, something would fall under the concept tiger if, and only if, it has the latter properties. Or perhaps lemon can be defined as, say, pale yellow, tart, oval citrus fruit and so forth; it is necessary and sufficient for belonging to the extension of lemon to have these features. And once again, the idea is that a subject would possess the concept tiger or lemon only if he or she knows these definitions.

It is commonplace to use specific Latin terminology in such cases: If it is definitions that are under [Page 151]discussion, the concept being defined, such as bachelor, is called “the definiendum,” and what is offered as the definition, such as unmarried man, “the definiens.” Analogously, in the case of analysis, what is analyzed is “the analysandum,” and what provides the analysis “the analysans.”

The classical theory of concepts is deeply rooted in the tradition of western philosophy: In Plato's dialogues, Socrates is described as asking for classical analyses of various concepts; definitions also have an important place in Aristotle's thought. In early modern philosophy, the classical theory was also dominant; one can find expressions of it in the works of René Descartes, Blaise Pascal, Baruch Spinoza, and especially John Locke, for example. It is also clearly present in the early 20th century in the thinking of Bertrand Russell, G. E. Moore, and the logical positivists and has indeed been a cornerstone of the traditional analytic philosophy, which emphasized conceptual analysis so strongly. In more recent philosophy, Frank Jackson and Christopher Peacocke, for example, have advocated variants of the classical theory.

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