51 Wittgenstein teaches in the Tractatus (cp. note 46 to this chapter where further cross-references are given) that philosophy cannot propound propositions, and that all philosophical propositions are in fact senseless pseudo-propositions. Closely connected with this is his doctrine that the true task of philosophy is not to propound sentences but to clarify them: ‘The object of philosophy is the logical clarification of thoughts.—Philosophy is not a theory but an activity. A philosophical work consists essentially of elucidations.’ (Op. cit., p. 77.)
The question arises whether this view is in keeping with Wittgenstein’s fundamental aim, the destruction of metaphysics by unveiling it as meaningless nonsense. In my The Logic of Scientific Discovery (see especially pp. 311 ff.), I have tried to show that Wittgenstein’s method leads to a merely verbal solution and that it must give rise, in spite of its apparent radicalism, not to the destruction or to the exclusion or even to the clear demarcation of metaphysics, but to their intrusion into the field of science, and to their confusion with science. The reasons for this are simple enough.
(1) Let us consider one of Wittgenstein’s sentences, for example, ‘Philosophy is not a theory but an activity’. Surely, this is not a sentence belonging to ‘total natural science (or the totality of the natural sciences)’. Therefore, according to Wittgenstein (see note 46 to this chapter), it cannot belong to ‘the totality of true propositions’. On the other hand, it is not a false proposition either (since if it were, its negation would have to be true, and to belong to natural science). Thus we arrive at the result that it must be ‘meaningless’ or ‘senseless’ or ‘nonsensical’; and the same holds for most of Wittgenstein’s propositions. This consequence of his doctrine is recognized by Wittgenstein himself, for he writes (p. 189): ‘My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless. .’ The result is important. Wittgenstein’s own philosophy is senseless, and it is admitted to be so. ‘On the other hand’, as Wittgenstein says in his Preface, ‘the truth of the thoughts communicated here seems to me unassailable and definite. I am, therefore, of the opinion that the problems have in essentials been finally solved.’ This shows that we can communicate unassailably and definitely true thoughts by way of propositions which are admittedly nonsensical, and that we can solve problems ‘finally’ by propounding nonsense. (Cp. also note 8 (2, b) to chapter 24.)
Consider what this means. It means that all the metaphysical nonsense against which Bacon, Hume, Kant, and Russell have fought for centuries may now comfortably settle down, and even frankly admit that it is nonsense. (Heidegger does so; cp. note 87 to chapter 12.) For now we have a new kind of nonsense at our disposal, nonsense that communicates thoughts whose truth is unassailable and definitive; in other words, deeply significant nonsense.
I do not deny that Wittgenstein’s thoughts are unassailable and definitive. For how could one assail them? Obviously, whatever one says against them must be philosophical and therefore nonsense. And it can be dismissed as such. We are thus faced with that kind of position which I have described elsewhere, in connection with Hegel (cp. note 33 to chapter 12) as a reinforced dogmatism. ‘All you need’, I wrote in my Logik der Forschung (now translated as The Logic of Scientific Discovery: see p. 51), p. 21, ‘is to determine the conception of “sense” or of “meaning” in a suitably narrow way, and you can say of all uncomfortable questions that you cannot find any “sense” or “meaning” in them. By recognizing the problems of natural science alone as “meaningful”, every debate about the concept of meaning must become nonsensical. Once enthroned, the dogma of meaning is for ever raised above the possibility of attack. It is “unassailable and definitive”.’
(2) But not only does Wittgenstein’s theory invite every kind of metaphysical nonsense to pose as deeply significant; it also blurs what I have called (op. cit., p. 7) the problem of demarcation. This he does because of his naive idea that there is something ‘essentially’ or ‘by nature’ scientific and something ‘essentially’ or ‘by nature’ metaphysical and that it is our task to discover the ‘natural’ demarcation between these two. ‘Positivism’, I may quote myself again (op. cit., p. 8), ‘interprets the problem of demarcation in a naturalistic way; instead of interpreting this question as one to be decided according to practical usefulness, it asks for a difference that exists “by nature”, as it were, between natural science and metaphysics.’ But it is clear that the philosophical or methodological task can only be to suggest and to devise a useful demarcation between these two. This can hardly be done by characterizing metaphysics as ‘senseless’ or ‘meaningless’. First, because these terms are better fitted for giving vent to one’s personal indignation about metaphysicians and metaphysical systems than for a technical characterization of a line of demarcation. Secondly, because the problem is only shifted, for we must now ask: ‘What do “meaningful” and “meaningless” mean?’ If meaningful’ is only an equivalent for ‘scientific’, and ‘meaningless’ for ‘non-scientific’, then we have clearly made no progress. For reasons such as these I suggested (op. cit., 8 ff., 21 f., 227) that we eliminate the emotive terms ‘meaning’, ‘meaningful’, ‘meaningless’, etc., from the methodological discussion altogether. (Recommending that we solve the problem of demarcation by using falsifiability or testability, or degrees of testability, as criterion of the empirical character of a scientific system, I suggested that it was of no advantage to introduce ‘meaningful’ as an emotive equivalent of ‘testable’.) * In spite of my explicit refusal to regard falsifiability or testability (or anything else) as a ‘criterion of meaning’, I find that philosophers frequently attribute to me the proposal to adopt this as a criterion of meaning or of ‘meaningfulness’. (See, for example, Philosophic Thought in France and in the United States, edited by M. Farber, 1950, p. 570.) *
But even if we eliminate all reference to ‘meaning’ or ‘sense’ from Wittgenstein’s theories, his solution of the problem of demarcating science from metaphysics remains most unfortunate. For since he identifies ‘the totality of true propositions’ with the totality of natural science, he excludes all those hypotheses from ‘the sphere of natural science’ which are not true. And since we can never know of a hypothesis whether or not it is true, we can never know whether or not it belongs to the sphere of natural science. The same unfortunate result, namely, a demarcation that excludes all hypotheses from the sphere of natural science, and therefore includes them in the field of metaphysics, is attained by Wittgenstein’s famous ‘principle of verification’, as I pointed out in Erkenntnis, 3 (1933), p. 427. (For a hypothesis is, strictly speaking, not verifiable, and if we speak loosely, then we can say that even a metaphysical system like that of the early atomists has been verified.) Again, this conclusion has been drawn in later years by Wittgenstein himself, who, according to Schlick (cp. my The Logic of Scientific Discovery, note 7 to section 4), asserted in 1931 that scientific theories are ‘not really propositions’, i.e. not meaningful. Theories, hypotheses, that is to say, the most important of all scientific utterances, are thus thrown out of the temple of natural science, and therefore put on a level with metaphysics.
Wittgenstein’s original view in the Tractatus can only be explained by the assumption that he overlooked the difficulties connected with the status of a scientific hypothesis which always goes far beyond a simple enunciation of fact; he overlooked the problem of universality or generality. In this, he followed in the footsteps of earlier positivists, notably of Comte, who wrote (cp. his Early Essays on Social Philosophy, edited by H. D. Hutton, 1911, p. 223; see F. A. von Hayek, Economica, VIII, 1941, p. 300): ‘Observation of facts is the only solid basis of human knowledge ... a proposition which does not admit of being reduced to a simple enunciation of fact, special or general, can have no real and intelligible sense.” Comte, although he remained unaware of the gravity of the problem hidden behind the simple phrases ‘general fact’, at least mentions this problem, by inserting the words ‘special or general’. If we omit these words, then the passage becomes a very clear and concise formulation of Wittgenstein’s fundamental criterion of sense or meaning, as formulated by him in the Tractatus (all propositions are truth-functions of, and therefore reducible to, atomic propositions, i.e. pictures of atomic facts), and as expounded by Schlick in 1931.—Comte’s criterion of meaning was adopted by J. S. Mill.
To sum up. The anti-metaphysical theory of meaning in Wittgenstein’s Tractatus, far from helping to combat metaphysical dogmatism and oracular philosophy, represents a reinforced dogmatism that opens wide the door to the enemy, deeply significant metaphysical nonsense, and throws out, by the same door, the best friend, that is to say, scientific hypothesis.