Logické výrazivo v přirozeném jazyce

The article attempts to elucidate the meaning of the term “logical expression”, which is commonly used in discussions in the area of the philosophy of language and the philosophy of logic. It focuses on “natural” logical expressions, which, according to a common view, constitute a specific category of expressions of individual national languages. Alternative approaches to the defining of logical expression are examined – definition by itemisation, Bolzanian definition based on the substitutability of expressions in analytically true (or false) judgements, and the Brandomian account which construes logical vocabulary as playing an expressive role. It is shown that each of these delineations evokes a number of questions which must be answered before philosophical theories can successfully build on a concept of logical expression.