The paper tries to separate two opposite features of natural languages. Plato was first who had noticed both of them. The one characteristic of languages, well known to the logicians and all scientists consists in the capability of languages to name things and to define meanings and accordingly to communicate positive ideas and unambiguous concepts explicitely. The second characteristic connected with the evolutionary features of natural languages is the problematic one. It is relatively hidden and for us it is not (...) easy to observe its nature. It rests upon the operation of the delimitation of ideas during the process of understandings – the meanings of expressions are established and the expressions of meanings are chosen on the background of others expressions and meanings in the whole matter of language. In this paper the second feature of languages is demonstrated by means of Ferdinand de Saussure´s Cours de linguistique générale. It is claimed that de Saussure´s conception of the ‘value’ is comparable with Quine´s the indeterminacy of translation. (shrink)