A distinction that assumed great importance in the work of Carnap, particularly in his Logical Syntax of Language (1934). In the material mode of speech objects and their relations are the topic; in the formal mode, language itself is mentioned. The distinction thus corresponds to the use/mention distinction. But for Carnap the background is the ‘quasisyntactical sentence’, in which features disguised as properties of objects are actually syntactic in character. Thus ‘five is a number’ is the material mode of what can be put in the formal mode as ‘“five” is a number-word’. Revealing the statement as basically syntactic in character removes the appearance of a deep logical or metaphysical truth. The cluster of ideas represents Carnap's belief that the logic of science is in fact nothing but the syntax of the language of science. The device of making a sentence the topic, instead of what the sentence purports to refer to, is sometimes referred to as semantic ascent. Correspondingly semantic descent is the move from an assertion about the application of a piece of language to use of that piece of language itself: the shift from ‘“five” is a number word’ to ‘five is a number’. Although many writers see semantic ascent and descent as moves that can be freely used, others worry about the shifts of meaning involved. There is a deal of difference between, for instance, allowing that it is a conventional matter that ‘five’ is a number-word, and taking it to be a conventional matter that five is a number. See also disquotational theory of truth.