type–token distinction as drawn by Peirce, the contrast between a category and a member of that category. An individual or token is said to exemplify a type; it possesses the property that characterizes that type. In philosophy this distinction is often applied to linguistic expressions and to mental states, but it can be applied also to objects, events, properties, and states of affairs. Related to it are the distinctions between type and token individuation and between qualitative and numerical identity. Distinct tokens of the same type, such as two ants, may be qualitatively identical but cannot be numerically identical. Irrespective of the controversial metaphysical view that every individual has an essence, a type to which it belongs essentially, every individual belongs to many types, although for a certain theoretical or practical purpose it may belong to one particularly salient type (e.g., the entomologist’s Formicidae or the picnicker’s buttinsky).
The type–token distinction as applied in the philosophy of language marks the difference between linguistic expressions, such as words and sentences, which are the subject of linguistics, and the products of acts of writing or speaking (the subject of speech act theory). Confusing the two can lead to conflating matters of speaker meaning with matters of word or sentence meaning (as noted by Grice). An expression is a linguistic type and can be used over and over, whereas a token of a type can be produced only once, though of course it may be reproduced (copied). A writer composes an essay (a type) and produces a manuscript (a token), of which there might be many copies (more tokens). A token of a type is not the same as an occurrence of a type. In the previous sentence there are two occurrences of the word ‘type’; in each inscription of that sentence, there are two tokens of that word.
In philosophy of mind the type–token distinction underlies the contrast between two forms of physicalism, the type–type identity theory or type physicalism and the token–token identity theory or token physicalism. See also ACTION THEORY, PEIRCE, PHILOSO- PHY OF MIN. K.B.