Most generally, the unit of communication: the smallest entity whose production constitutes a message, such as an assertion, a command, or a question. Given such factors as variations of phonetics or spelling, recognition of two speech acts as the production of the same sentence is already a matter of interpretation, but one that is usually automatic to speakers of the same native language. Grammatically a sentence is the unit whose structure is subserved by other recognized features of a language. The priority of the sentence in much analytic philosophy is summed up in Frege’s dictum that it is only in the context of a sentence that words have meaning. The least controversial interpretation of the slogan is that for a word to mean anything is simply for it to contribute systematically to the meaning of whole sentences in which it is embedded. A word is not a thing with its own ‘projection’ onto parts of the world; instead, the presence of a word (or more accurately, a morpheme) is a feature of a sentence, one which plays a role in determining its meaning, and whose variation systematically determines the meaning of related sentences. A more radical extension of the same line suggests that it is only in the context of a whole theory, or world view, or language, that a single sentence means anything. In the terminology of Dummett, according priority to words is semantic ‘atomism’, to sentences, ‘molecularism’, and to anything larger, ‘holism’. See also Duhem thesis.