Sir A.J. Ayer, late 1980s.Geoff A Howard/Alamy
It is the mark of a genuine factual proposition, not that it should be equivalent to an experiential proposition, or any finite number of experiential propositions, but simply that some experiential propositions can be deduced from it in conjunction with certain other premises without being deducible from those other premises alone.
As Ayer admitted in his second edition, however, this formulation lets in too much, including the propositions of metaphysics. From “The Absolute has no history” and “If the Absolute has no history, this is red,” it follows that “This is red,” which is certainly an experiential proposition. Nor were subsequent attempts, by Ayer and others, to tighten up the formulation generally accepted as successful, for in every case it was possible to produce objections of a more or less persuasive kind.
This result may seem paradoxical, for at first glance the Positivist case is extremely impressive. It certainly sounds odd to say that metaphysical sentences are literally without meaning, seeing that, for example, they can be replaced by equivalent sentences in the same or another language. But if the term meaning is taken here in a broad sense and understood to cover significance generally, the contention is by no means implausible. What is now being said is that metaphysical systems have internal meaning only; the terms of which they consist may be interdefinable but perhaps do not relate to anything outside the system. If that were so, metaphysics would in a way make sense but for all that would be essentially idle; it would be a game that might amuse but could hardly instruct. The Positivists confront the metaphysician with the task of showing that this criticism is not correct. Whatever difficulties are involved in formulating a principle of verifiability, the challenge can hardly be ignored. Moore and Wittgenstein
The Positivists were not the only modern critics of metaphysics. G.E. Moore never argued against metaphysics as such, but nevertheless he produced criticisms of particular metaphysical theses that, if accepted, would make metaphysical speculation difficult, if not impossible. It was characteristic of a certain type of philosopher, according to Moore, to advance claims of a highly paradoxical nature—to say, for instance, that “Time is not real” or that “There are no such things as physical objects.” Moore’s case for rejecting such claims was that they go against the most central convictions of common sense, convictions that people accept unhesitatingly when they are not doing philosophy. Men constantly say that they did this before that, that things are better or worse than they were; from time to time they put off things until later or remark that tomorrow will be another day. Moore took these facts as definitive proof of the reality of time and definitive disproof of any metaphysical theory that denied it. Supporters of Bradley, the philosopher here criticized, replied that Moore had missed the point. Bradley never denied the truth of temporal propositions as used in the description of appearances; what he questioned was the coherence and ultimate tenability of the whole temporal way of thinking. As Rudolf Carnap, a Logical Positivist, was to put it, he raised an external question and was given an internal answer by Moore. It was an answer, however, that carried considerable conviction. The simple denial of what seem to be obvious facts had always been part of the stock-in-trade of metaphysicians; they make much of the distinction between appearance and reality. Moore may not have demonstrated the impropriety of this insistence, but at least he made it necessary for the metaphysician to be more circumspect, to explain explicitly what he was denying and what he was ready to accept, and so to make his own case sharper and thus easier to confirm or reject.
Moore’s implied criticisms of metaphysics lead on naturally to those of Wittgenstein. Moore took his stand on common sense, whereas Wittgenstein based his on living language. Arguing that men are each involved in a multitude of language games or autonomous linguistic activities, insofar as they are scientific investigators, moral agents, litigants, religious worshipers, and so on, Wittgenstein asked in what language game the claims and questionings of philosophers arose. He replied that there was no genuine linguistic context to which they belonged; philosophical puzzlement was essentially idle. Philosophers were preoccupied with highly general questions; they aspired to solve the problem of meaning or the problem of reality. Against that Wittgenstein argued that words and sentences have meaning as used in particular contexts; there is no single set of conditions that has to be fulfilled if they are to be thought meaningful. Equally, there is no single set of criteria that has to be satisfied by everything one takes to be real. Sticks and stones and men are taken as real in everyday discourse, but so are numbers in the discourse of mathematicians, and so is God in the discourse of religious men. There is simply no warrant for preferring one of these above the others—for saying, for example, with persons of an Empiricist turn of mind, that nothing can be real that does not have existence in space and time.
Wittgenstein’s antipathy to metaphysical philosophy was in part based on self-criticism; in his early work the Tractatus Logico-Philosophicus, published in 1922, he had himself tried to give a general account of meaning. At least one doctrine of that enigmatic book survived in his later thought: the distinction between saying and showing. Wittgenstein in the Tractatus sought to pronounce on “what can be said” and came to the conclusion that only “propositions of natural science” can be. Though at this stage he spoke as if metaphysical statements were senseless, his motives for doing so were very different from those of the Positivists. The latter saw metaphysics as an enemy of science; in their view there was only one way to understand the world, and that was in scientific terms. But Wittgenstein, though agreeing that science alone can be clear, held that scientific thought has its limitations. There are things that cannot be said but can, nonetheless, be shown; the sphere of the mystical is perhaps a case in point. Unlike his Viennese contemporaries, Wittgenstein had no wish to rule out of court the thought that there are more things in heaven and earth than can be compassed in the language of science; writers whom he admired—such as Blaise Pascal, a 17th-century French scientist and writer on religious subjects, and Søren Kierkegaard, a Danish philosopher and theologian who is regarded as the founder of modern Existentialism—had discoursed of such matters in a way that was highly illuminating. They had made clear, however, that, just as one here went beyond the province of science, so also one went beyond that of philosophy. For them the idea that the metaphysician is privy to the most important of all things is absurd. There may be a sense in which men transcend everyday experience in moments of religious feeling or artistic insight, but there is no justification for thinking that when they do they arrive at the metaphysician’s Absolute. As Kierkegaard said, the man who looks for speculative proofs in the sphere of religion shows that he does not understand that sphere at all. Religious philosophers
It is important, in considering current criticisms of metaphysics, to appreciate that this discipline is now under double attack. In the first place, it must face the assault of those who regard it as a rival to science; it is against this assault that sympathizers like R.G. Collingwood, a British philosopher, historian, and archaeologist, seek to defend it. But metaphysics is also in disfavour among many religious philosophers. In earlier days, partisans of religion, and more generally believers in a spiritual order, looked to metaphysics to vindicate their claims against skeptical attack; now they are altogether more reluctant to do so. The continuing controversy about metaphysics has no doubt influenced this development; it scarcely seems sensible to take refuge in a fortress whose walls are so frequently breached. There is, however, another motive that operates here: the feeling that metaphysics is not only dubious but, worse, unnecessary. In an age whose tendencies are antiphilosophical rather than philosophical, there is widespread acceptance of the view that religion and morals, and for that matter science and history, are their own justification; none of them stands in need of a certificate of respectability from philosophy, and any pretense by metaphysicians to supply or refuse such a certificate must be without foundation. Though this view is widespread, it is even so not unchallenged; there are persons who find the fragmentation it involves—belief in God on Sundays, belief in science for the rest of the week—intolerable. For such persons, at least, the search for metaphysical truth and metaphysical answers must retain its fascination. William Henry Walsh Tendencies in contemporary metaphysics Tendencies in the United States