Material Mode of Speech
Material Mode of Speech
A description introduced by Carnap and based upon his distinction between “object-sentences” and “syntactical sentences”. A sentence is syntactical if it can be translated into (is materially equivalent to) another sentence of the same language which refers only to signs or formal properties of and relations between signs. All non-syntactical sentences are said to be object sentences.
In a fully symbolized language (a “calculus”) any sentence can be assigned to one of these classes by inspecting the formal properties of the sentence-token. In a “natural” language such as English, the formal properties of a sentence-token may indicate that it is an object-sentence when it is in fact syntactical. Such a sentence (also said to be quasi-syntactical) is expressed in the material mode of speech. When translated into an overtly syntactical sentence it is then said to be expressed in the formal mode of speech.
R. Carnap, Logical Syntax of Language, 284 ff. (for a more exact account). — M.B.