A sentence must use old expressions to tell us something new.

A sentence must use old expressions to communicate a new sense. A sentence must be essentially associated with the situation it tells us about. That association is precisely the fact that the sentence is the situation's logical image. A sentence states something only in so far as it is an image.

In a sentence, a situation is assembled on trial, as it were. Instead of, 'This sentence makes sense in such and such a way', we can simply say, 'This sentence depicts such and such a situation'. A name stands for one thing, another for another, and, they are combined with one another; thus the whole - like a tableau - presents a matter of fact. The principle that signs represent objects makes sentences possible.

Wittgenstein consider it fundamental that the 'logical constants' do not stand for something; that the logic of facts cannot be representational. A sentence is only an image of a situation in so far as it was organized logically. (Even the sentence 'Ambulo' is composite; for its stem with a different ending yields a different sense, and so does its ending with a different stem.)