H. P. Grice, "Complexum propositionale"

COMPOSITUM -- compositionality Philosophy of language A language is compositional if its syntactically complex expressions, for example sentences, derive their meanings from their syntactic structures and the meanings of their lexical constituents. For instance, the meaning of the sentence “Snow is white” is a function of the meaning of “snow,” the meaning of “white,” and the places that these expressions occupy in the subject-predicate structure of the sentence. The semantic feature of compositionality has a wide application in the philosophy of language. It also forms the basis for the truth-conditional theory of meaning. A satisfactory semantic theory should explain how the meanings of small expressions contribute to the meanings of larger ones that contain them. It has become the principle that the meaning of an expression is a function of the meaning of its parts and the syntactic structure of these parts. This principle is generally ascribed to Frege and is also called the Fregean principle. “The principle of compositionality: The meaning of an expression is a monotonic function of the meaning of its parts and the way they are put together.” Cann, Formal Semantics compound thought Logic, philosophy of language Analogous to a compound sentence, which consists of two or more sentences. Frege introduced the notion of compound thought, which is a whole combined out of two or more thoughts by something that is not a thought. As a compound sentence is itself a sentence, a compound thought is itself a thought, and it can also be compounded into other thoughts. Frege distinguishes six different types of compound thought. With A and B representing different single thoughts, they are: (1) A and B; (2) (not A) and (not B); (3) (not A) and B; (4) not (A and B); (5) not (not A) and (not B); and (6) not ((not A) and B). Frege believed that in a mathematical compound thought, if one component is replaced by another thought having the same truth-value, the new compound thought has the same true-value as the original. The idea is central to propositional logic. “By ‘compound thought’ I shall understand a thought consisting of thoughts, but none of thoughts alone.” Frege, Collected Papers