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Philosophy against Misosophy
Foreword to Arthur Pap, Semantics and Neces-sary Truth: An Inquiry into the Foundations of Analytic Philosophy, New Haven and London: Yale University Press, 1958, v-xii.
Foreword to Arthur Pap,
Semantics and Necessary Truth
Brand Blanshard
This book seems to me the most thorough study of its subject in the English language. That the subject is technical and exacting will be conceded by anyone who sits down to the book seriously. Is the problem worth the effort on the part of the writer and the reader? It is undoubtedly. Philosophers have come to see more clearly than ever before that the problem is central not only to logic and the theory of knowledge, but to metaphysics also. It may be well to develop this a little, not for the sake of the specialist, but for the sake of students who may approach the problem without previous acquaintance with it.
Speculative philosophers of the past have placed their chief reliance on a faculty or process called “reason.” It was supposed to provide an insight different in type from perception or common sense or natural science, and to be far greater in sweep and certainty. Indeed it made philosophy possible. The thinker who had command of it was in need of nothing more except a limited experience and an armchair. It was true that instruments and experiments were necessary if one were to enter the world of science, but if one wanted the fundamental truth even about that—about how it came into being, what stuff it was made of, what was the ultimate pattern on which it was put together, how our minds were related to it—the right course was to sit down with such knowledge as one had and use one’s “reason” on it. That knowledge was of course fragmen-tary, but by reason we could interpret it and round it out into a consistent whole of theory.
The great metaphysicians all did this. St. Thomas saw, or thought he saw, that given the frame of things disclosed by common experience, it must have been created by a Deity with such and such attributes. Descartes held that from the existence of his own thought he could infer with certainty the nature of man, the world, and God. Spinoza, starting with the belief in substance, undertook to spin out in Euclidian fashion a complete metaphysical system; and Hegel, Bradley, Royce, and McTaggart repeated the cosmic deduction, each in his own way. They all relied on necessary truths and necessary reasoning. And by a necessary truth they meant more than one that was merely true; it had to be true; we could see that it could not be other than true. That is what made it so compelling. Crows might, for all we could see, have been flamingo-colored; hydro-gen sulphide might have had the odor of gardenias; but two and two could not have been anything but four. If philosophy would only hold itself on the straight track of necessity, proceeding from necessary starting points through necessary deductions to conclusions that were therefore necessary, it could arrive at a view of the world that would have the clearness and cogency of a mathematical demonstration.
That we do possess occasional insights of this kind seems clear enough. But there is something mysterious about our having them at all. Why it is that in some matters a thousand unbroken instances of A’s being B still leaves us less than sure that it will be so tomorrow, while in others a single case will give us certainty? We cannot be wholly sure that the sun will rise tomorrow; it is quite conceivable that it should explode or that some meteor should abolish the earth before there is any morrow. But we do know with certainty that whether we have a morrow or not, any two planets and any other two will still make four. How do we come by this certainty about times and places that outrun our experience?
Philosophers have been puzzled by this problem for more than two thousand years. Readers of the Platonic dialogues will recall that Socrates was already aware both of the existence of such knowledge and of the difficulty of accounting for it. The most dramatic demonstration on record of the existence of a priori knowledge is the familiar incident in the Meno in which Socrates, on a walk by the seaside, calls to an unlettered slave boy and, with the aid of a figure drawn in the sand and a little timely nudging, gets him to establish a geometrical theorem that he had never learned or heard of. Socrates suggested—how much in earnest it is hard to say—that such insight must be accounted for through the retention of knowledge gained in an earlier life. But this only puts the problem one step back, for the puzzle would still remain: how in this earlier existence could we have arrived at certainty from a limited experience?
In philosophic history there have been five important attempts, curiously diverse from each other, to explain our possession of necessary knowledge. Perhaps the simplest is that of the traditional rationalist. His theory is that we grasp necessity because it is there to grasp; things in nature are actually connected by logical and mathematical relations, and we can apprehend these relations as clearly as we can shapes or motions. It is true that we cannot sense a necessary relation; when we say we see that two and two make four, we cannot mean that we see this with our eyes. But we do see it in the sense of apprehending it as necessarily true, and we must assume the existence in us of whatever organ or faculty is required for this apprehension—call it intelligence, understanding, reason, or what you will. The law of contradiction, for example, is not merely a “law of thought”; it is a law that governs the structure of everything that exists. That is why Bradley could use it as the base for a large metaphysical edifice.
Empiricists have always been suspicious of this kind of knowledge and have often tried to explain it away. The most uncompromising of these attempts, which is the second on our list of theories, was made by John Stuart Mill. With great boldness he argued that all apparently necessary truths were really empirical generali-zations. If A and B are presented together often enough and with no exceptions, we come in time to lose the power of separating them even in thought. “Two straight lines do not enclose a space.” Whenever we have seen two straight lines, either parallel to each other or converging at the corner of a table or a street, this negative property has accompanied them, of not enclosing a space; it is confirmed hourly with never an exception, so that we have reached the point of thinking that it goes with such lines necessarily. Does it really? Mill said No. What links the ideas is psychological association, and this, however often confirmed, always falls short of logical necessity. Such necessity is a fiction.
This theory has not stood up well. It carried with it the implication that “necessary truths,” even though we had never known an exception, might have one tomorrow; all we could say was that this was very unlikely. But is it not more than unlikely; is it not plainly impossible? We do not really believe that in some remote bank a case may occur in which two pennies and two others go on strike and perversely make three or five. Of course some weary teller may suppose they do, but this is because he is sleepy or drunk or drugged. We somehow know that two and two could never under any circumstances make anything but four, which means that we possess the knowledge which Mill denied.
The third theory was that of Kant. Unlike Mill, he admitted that we have insight that is both necessary and universal; these were the two marks of a priori knowledge, and he held that we had a remarkable range of such knowledge, extending from logic and mathematics to physics and even ethics. How are we to account for it? He devoted his first and greatest Critique to answering that question, and the answer was a long one, since it involved nothing less than a Copernican revolution in philosophy. To put the answer with an almost brutal brevity, the reason why we can be sure that if we ever reach the moon or Mars we shall find lines and numbers behaving as they do here is that we manufacture them ourselves, whether we know it or not. The frames of logic and arithmetic, space and time, are imposed on experience from within; they are like spectacles grown to our noses, lenses through which we look out at the world; and since they would still be there on our noses if we went to the moon or Mars, we can be sure beforehand how in general things would look. They would look that way because we make them that way. Can we say, as the rationalists do, that such a priori knowledge tells us what the world is really like? Unfortunately not, said Kant. It can tell us what the world is bound to seem like, but after all, the world we see through the “categories” is only a world of seeming, a realm of “phenomena,” and we have no way of removing the spectacles and looking at things directly. Our certainty about the world of phenomena is bought at the price of an invincible ignorance about things in themselves.
Kant's theory was elaborated with an ingenuity and thoroughness that has given it a vast influence. Yet few philosophers and fewer scientists today accept it. Two discoveries, made since Kant wrote, have gone far toward discrediting it. The first was the discovery of non-Euclidian geometries. Kant accepted the view of Euclid that the whole of traditional geometry consisted of necessary truth; self-evident theorems were self-evidently demonstrated from axioms self-evidently true. But early in the nineteenth century the Russian mathematician Lobachevski began to have doubts about the self-evidence of some Euclidian starting points, notably the postulate of parallels, which states that through a point outside a given line only one parallel to that line is possible. He tried the experiment of assuming that more than one parallel could be drawn and found that with that assumption he could still construct a consistent geometry. Euclid's geometry was not, then, as Kant thought, the only possible one.
Kant might have replied that it was at any rate the only one that applied to nature. But on this point too his theory encountered trouble; it had the great misfortune of running afoul of Einstein. In working out the implications of his theory of relativity, Einstein was able to calculate where a certain star should be seen during a solar eclipse on the assumptions first that the galaxies were arranged on a Euclidian pattern and then on a non-Euclidian. The observation confirmed the latter. Kant’s theory never looked the same again.
A fourth theory is of more recent appear-ance, though one of its proponents, F. C. S. Schiller, maintained that it was in substance as old as Protagoras. This is the pragmatic theory. In an essay on “Axioms as Postulates,” Schiller argued for it in an extreme form, but other and more plausible forms have been offered by Henri Poincaré, John Dewey, C. I. Lewis, and Ernest Nagel. Its contention is that even those ultimate principles that have been accepted because they seemed self-evidently necessary are really adopted because they are the most efficient means to ends. Why, for example, do we accept the law of contradiction? Because of its necessity? No, but because of its usefulness. We find that by using it in our intellectual practice we can make our knowledge more precise, coherent, and systematic, which we very much want it to be.
But this pragmatic line of argument always seems to sag down under pressure. Why should we want our ideas to be more precise, or more coherent, or more systematically organized? Suppose someone announced that he was not interested in these things, and personally preferred vagueness, incoherence, and chaos. We should regard such a person as excessively foolish if not unbalanced, and the reason is plain enough: It is that precision, coherence, and order are not themselves the end of the line; we want them because we want something else to which they are means. We want them because they are aids to truth, because only as thought embodies them can we see things as they are. Conformity to the law of contradiction is the accepted condition of conformity to fact. That, not its practical usefulness, is the reason why we cling to it.
All of these theories have in recent years been pushed off into the shadow by a fifth theory, “logical empiricism.” It agrees with Kant and the rationalists in holding that we do have necessary knowledge, inexplicable by any run of sense experiences. But having made this clear, the logical empiricists turn round on the rationalist and say that this knowledge, far from revealing the nature of things, reveals nothing but our own intentions. They argue for this view in three ways which converge to the same conclusion. Necessary truths, they maintain, are linguistic, conventional, and analytic.
First they are linguistic. This means that they are merely statements of how we propose to use words. When we say, “A straight line is the shortest distance between two points,” we are saying that we use the phrase “straight line” only of those lines that are the shortest between their ends, and never of others; the statement thus explains our usage. Now usage is plastic to our preferences; we can define our terms differently if we care to, even the fundamental ones. Hence, secondly, these necessary statements are conventions. “It is perfectly conceivable that we should have employed different linguistic conventions from those which we actually do employ,” said A. J. Ayer; “the rules of language are in principle arbitrary,” said Moritz Schlick; even the postulates and rules of logical inference, said Carnap, “may be chosen quite arbitrarily.” But if the principles of logic reflect our changeable preferences, they cannot also reflect the enduring structure of things; we are deluded if we try to make laws of nature out of mere human conventions. That these necessary truths are really conventions is confirmed if we note, thirdly, that they are all analytic, all attempts to set out, in whole or part, what we mean. Why is it that we refuse to call straight any line that is not the shortest one? Surely because being the shortest is part of what we mean by “straight,” so that to deny that it is the shortest would be self-contradiction. To say that two and two are four is to say that what we mean by these phrases is identical. That is why we remain unmoved if anyone tries to point out that there are instances to the contrary, that two wolves and two lambs, or two drops of water and two others, sometimes do not make four. We should reply that we are not talking about events in nature, but about what we mean by two and two. We know very well what we mean, and we know that it is quite independent of any such events.
Of course if this theory is true, it has far-reaching philosophical consequences. The instrument that philosophers have called “reason,” the tool on which they have mainly relied in building their cosmic constructions, will be for this purpose discredited. Rationalists have always assumed that the more severely logical their thinking, the more likely they were to arrive at the truth about the world. But if the very statements they take to report most faithfully the nature of things report only their own meanings and tell them nothing about existence, their major tool turns out to be a broken reed.
No one saw this more clearly than Arthur Pap. Without ignoring the other theories, he plainly regards this last as the really formidable one, which philosophy must now reckon with. He devotes the larger part of his book to stating it, reviewing the various forms of it, qualifying, amending, and criticizing it, and refuting with devastating force some of its more popular forms. He was often considered a logical empiricist himself, and that he belongs in the camp of analysis rather than that of speculative philosophy is abundantly clear. But the theory that emerges after running the gauntlet of this long examination is a very chastened empiricism indeed. Here I shall leave him to tell his own highly competent story.
There is a personal side to this story which he would not have cared to tell, but which those who read and admire this book may wish to know. I shall allow myself a concluding word about it.
Arthur Pap was born in Zürich, in German-speaking Switzerland, the son of a successful businessman of that city. He lived there till he was nineteen, with German as his native language, and harboring thoughts of two very different but very German careers. One was a career in music; he was a sensitive musician and an accomplished pianist. The other was in philosophy, and with none other than Hegel as his master. Both dreams were halted abruptly when his family, finding the backwash of Hitlerism unbearable, even in Switzerland, emigrated to America.
Arthur Pap had to start out over again in a foreign country and with an alien language. It did not take him long to find himself here. He took a degree at Columbia, spent a year with Cassirer at Yale, and returned to the Columbia graduate school to win the Woodbridge prize for his doctoral thesis on “The A Priori in Physical Theory,” which was in a sense a preliminary study for the present book. He taught for brief periods at Chicago University, City College, the University of Oregon, Lehigh, and Yale. To his delight he was invited to serve in the year 1953-54 as Fulbright lecturer in Vienna, where he presented in his lectures an evaluation of the historic movement initiated by “the Vienna Circle” a quarter-century before. During his teaching years at Yale, he wrote, taught, and thought with a singular intensity—the intensity of a man whose true life was among ideas. In the same year the university gave him a promotion and the Yale Press published this book. After a long and stony path toward recognition, he seemed to have turned a corner and to be looking down an avenue of assured success. Then suddenly he was struck down. In the spring of the following year he suffered an attack of the kind of nephritis for which there is no known cause or cure. He died in September 1959, at the age of thirty-eight, leaving a wife and four young children.
His achievement in the less than twenty years he spent in his new country was far greater in quality and quantity than most philosophers manage in a lifetime. He wrote five books of notable subtlety and technical proficiency, besides a long list of articles in professional journals, contriving to throw them off while carrying a full load of teaching. If he had lived, he would no doubt have revised this book for its new edition and made it even better than it is. He would also have taken his place as one of the leading philosophers of our time; indeed many readers of this book will feel that he was already there. He has taken as its theme one of the central recurring issues of the theory of knowledge and explored it with a thoroughness and acuteness that are apparent on every page. It is hoped that this new edition of his book will make his name, his quality, and his achievement more widely known.
Posted March 20, 2007
