Wittgenstein’s treatise is, in brief, an ontological theory of logic. The nature of logic ensues here from the structure of the world, but it can also be said, the other way round, that there is nothing more appropriate than an inquiry into the essence of logic for elucidating the nature of the world. The world is the totality of facts; facts are combinations of “things”; things have content and form; form is space, time, and “color.” (Color corresponds to the qualitative aspect of reality as given by the senses.) The world is not the totality of things but of facts: this is important, as every fact involves a relation and every relation has a certain formal structure. It is this formal structure that makes possible language, which is nothing other than a logical picture of the world. There is a logical picture where there is agreement in structure between two facts. Thus, a sentence directly shows the structure of the fact that is its meaning. Sentences in general have meaning only on the general condition of it being ultimately possible to resolve even their most complex expressions into expressions that show the structure of the elementary facts of which the world is composed. If the expression is in a form such that its individual signs unequivocally correspond to the objects of the pictured fact, then we have to do with a fully analyzed sentence. Every sentence can be ultimately reduced to a fully analyzed form, thereby guaranteeing agreement between the thing and its picture. The entire world is expressible, but on the condition that the expression itself is part of the world, subject to the same general laws. A sentence has meaning only if it can be verified by the direct comparison of two facts: the sentence and its object. The whole of logic follows simply from the rules of picturing. “In logic it is not we who express, by means of signs, what we want, but in logic the nature of the essentially necessary signs itself asserts.” The so-called laws of logic are tautologies, i.e., combinations of sentential signs valid for all possible combinations of the truth-values of the elementary propositions. In logic, something of the very essence of the world is shown simply because the fundamental structure of nature is logical. One can never resist logic, nor sin against logic. A thought is always logical.
Wittgenstein’s theses, which look like wholly unprejudiced logical considerations and yet, as we see, in fact contain, implicit in their starting point, an entire objectivist, mathematical theory of being, were to provide the basis for a new polemical campaign ardently waged by certain members of the “Vienna Circle” against all “metaphysics.” It is a polemic which denies the so-called metaphysical propositions, those featuring concepts such as “principle,” “God,” “the absolute,” “nothingness,” etc., not only truth but—on the basis of Wittgenstein’s considerations on language as a logical picture of things—any meaning whatever. It must be emphasized here that these logicists take the word “meaning” in an uncommon acceptation, which presupposes their specific metaphysical theses (the logical atomism described above) as well as their theses on the nature of language. Nowhere, however, has there been a sustained attempt to show that this concept of meaning coincides with common, everyday use; these thinkers themselves are far from such a position. Up against the fact that people have for thousands of years taken propositions containing metaphysical names to be meaningful, they resort to a doubtless too facile comparison of metaphysics to music evoking emotions and moods; these authors deny that there is on any account thought going on here.