Great Throughts Treasury

This site is dedicated to the memory of Dr. Alan William Smolowe who gave birth to the creation of this database.

Karl Popper, fully Sir Karl Raimund Popper

Austro-British Scientific Philosopher and Professor at the London School of Economics

"All we can do is search for the falsity content in our best theory."

"Although I consider our political world to be the best of which we have any historical knowledge, we should beware of attributing this fact to democracy or to freedom. Freedom is not a supplier who delivers goods to our door. Democracy does not ensure that anything is accomplished ? certainly not an economic miracle. It is wrong and dangerous to extol freedom by telling people that they will certainly be all right once they are free. How someone fares in life is largely a matter of luck or grace, and to a comparatively small degree perhaps also of competence, diligence, and other virtues. The most we can say of democracy or freedom is that they give our personal abilities a little more influence on our well-being."

"Almost everyone... seems to be quite sure that the differences between the methodologies of history and of the natural sciences are vast. For, we are assured, it is well known that in the natural sciences we start from observation and proceed by induction to theory. And is it not obvious that in history we proceed very differently? Yes, I agree that we proceed very differently. But we do so in the natural sciences as well. In both we start from myths?from traditional prejudices, beset with error?and from these we proceed by criticism: by the critical elimination of errors. In both the role of evidence is, in the main, to correct our mistakes, our prejudices, our tentative theories?that is, to play a part in the critical discussion, in the elimination of error. By correcting our mistakes, we raise new problems. And in order to solve these problems, we invent conjectures, that is, tentative theories, which we submit to critical discussion, directed towards the elimination of error."

"Appealing to his [Einstein's] way of expressing himself in theological terms, I said: If God had wanted to put everything into the universe from the beginning, He would have created a universe without change, without organisms and evolution, and without man and man's experience of change. But he seems to have thought that a live universe with events unexpected even by Himself would be more interesting than a dead one."

"Aestheticism and radicalism must lead us to jettison reason, and to replace it by a desperate hope for political miracles. This irrational attitude which springs from intoxication with dreams of a beautiful world is what I call Romanticism. It may seek its heavenly city in the past or in the future; it may preach ?back to nature? or ?forward to a world of love and beauty?; but its appeal is always to our emotions rather than to reason. Even with the best intentions of making heaven on earth it only succeeds in making it a hell ? that hell which man alone prepares for his fellow-men."

"As for Adler, I was much impressed by a personal experience. Once, in 1919, I reported to him a case which to me did not seem particularly Adlerian, but which he found no difficulty in analyzing in terms of his theory of inferiority feelings, although he had not even seen the child. Slightly shocked, I asked him how he could be so sure. "Because of my thousandfold experience," he replied; whereupon I could not help saying: "And with this new case, I suppose, your experience has become thousand-and-one-fold.""

"As indicated by our example, methodological nominalism is nowadays fairly generally accepted in the natural sciences. The problems of the social sciences, on the other hand, are still for the most part treated by essentialist methods. This is, in my opinion, one of the main reasons for their backwardness."

"Astrologers were greatly impressed, and misled, by what they believed to be confirming evidence-so much so that they were quite unimpressed by any unfavorable evidence. Moreover, by making their interpretations and prophecies sufficiently vague they were able to explain away anything that might have been a refutation of the theory had the theory and the prophecies been more precise. In order to escape falsification they destroyed the testability of their theory. It is a typical soothsayer's trick to predict things so vaguely that the predictions can hardly fail: that they become irrefutable."

"Better our hypotheses die for our errors than ourselves."

"But I shall certainly admit a system as empirical or scientific only if it is capable of being tested by experience. These considerations suggest that not the verifiability but the falsifiability of a system is to be taken as a criterion of demarcation. In other words: I shall not require of a scientific system that it shall be capable of being singled out, once and for all, in a positive sense; but I shall require that its logical form shall be such that it can be singled out, by means of empirical tests, in a negative sense: it must be possible for an empirical scientific system to be refuted by experience. (1959)"

"But it is certainly not possible to insist on one hand that the formalism is complete and to insist on the other hand that its application to 'the actual' actually demands a step which cannot be derived from it."

"Every intellectual has a very special responsibility. He has the privilege and the opportunity of studying. In return, he owes it to his fellow men (or 'to society') to represent the results of his study as simply, clearly and modestly as he can. The worst thing that intellectuals can do - the cardinal sin - is to try to set themselves up as great prophets vis-…-vis their fellow men and to impress them with puzzling philosophies. Anyone who cannot speak simply and clearly should say nothing and continue to work until he can do so."

"But some of these theories are so bold that they can clash with reality: they are the testable theories of science. And when they clash, then we know that there is a reality; something that can inform us that our ideas are mistaken."

"Every solution of a problem raises new unsolved problems."

"Bold ideas, unjustified anticipations, and speculative thought, are our only means for interpreting nature: our only organon, our only instrument, for grasping her. And we must hazard them to win our prize. Those among us who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game."

"Contrary to the outstanding work of art, outstanding theory is susceptible to improvements."

"Darwinism is not a testable scientific theory, but a metaphysical research program. And yet, the theory is invaluable. I do not see how, without it, our knowledge could have grown as it has done since Darwin."

"But the (so-called) socialist revolution came first in one of the technically backward countries. And instead of the means of production producing a new ideology, it was Lenin's and Stalin's ideology that Russia must push forward with its industrialization ('Socialism is dictatorship of the proletariat plus electrification') which promoted the new development of the means of production."

"Do not allow your dreams of a beautiful world to lure you away from the claims of men who suffer here and now. Our fellow men have a claim to our help; no generation must be sacrificed for the sake of future generations, for the sake of an ideal of happiness that may never be realized."

"Every genuine test of a theory is an attempt to falsify it, or to refute it."

"Definitions.... are never really needed, and rarely of any use."

"From Plato to Karl Marx and beyond, the fundamental problem has always been: who should rule the state? (One of my main points will be that this problem must be replaced by a totally different one.)"

"Historically speaking all - or very nearly all - scientific theories originate from myths."

"Great men may make great mistakes."

"Evolution is not a fact. Evolution doesn't even qualify as a theory or as a hypothesis. It is a metaphysical research program, and it is not really testable science."

"Genuine philosophical problems are always rooted outside philosophy and they die if these roots decay."

"For it was my master who taught me not only how very little I knew but also that any wisdom to which I might ever aspire could consist only in realizing more fully the infinity of my ignorance."

"For myself, I am interested in science and in philosophy only because I want to learn something about the riddle of the world in which we live, and the riddle of man's knowledge of that world. And I believe that only a revival of interest in these riddles can save the sciences and philosophy from an obscurantist faith in the expert's special skill and in his personal knowledge and authority."

"History has no meaning."

"However, Marxism is no longer a science; for it broke the methodological rule that we must accept falsification, and it immunized itself against the most blatant refutations of its predictions. Ever since then, it can be described only as nonscience?as a metaphysical dream, if you like, married to a cruel reality."

"I am opposed to looking upon logic as a kind of game... One might think that it is a matter of choice or convention which logic one adopts. I disagree with this view."

"I do not believe that human lives may be made the means for satisfying an artist's desire for self-expression. We must demand, rather, that every man should be given, if he wishes, the right to model his life himself, as far as this does not interfere too much with others. Much as I may sympathize with the aesthetic impulse, I suggest that the artist might seek expression in another material. Politics, I demand, must uphold equalitarian and individualistic principles; dreams of beauty have to submit to the necessity of helping men in distress, and men who suffer injustice; and to the necessity of constructing institutions to serve such purposes."

"I appeal to the philosophers of all countries to unite and never again mention Heidegger or talk to another philosopher who defends Heidegger. This man was a devil. I mean, he behaved like a devil to his beloved teacher, and he has a devilish influence on Germany. ? One has to read Heidegger in the original to see what a swindler he was."

"I don't know whether God exists or not... Some forms of atheism are arrogant and ignorant and should be rejected, but agnosticism?to admit that we don't know and to search?is all right... When I look at what I call the gift of life, I feel a gratitude which is in tune with some religious ideas of God. However, the moment I even speak of it, I am embarrassed that I may do something wrong to God in talking about God."

"I have changed my mind about the testability and logical status of the theory of natural selection; and I am glad to have an opportunity to make a recantation."

"I have insisted that we must be tolerant. But I also believe that this tolerance has its limits. We must not trust those anti-humanitarian religions which not only preach destruction but act accordingly. For if we tolerate them, then we become ourselves responsible for their deeds."

"I have come to the conclusion that Darwinism is not a testable scientific theory, but a metaphysical research program."

"I do not overlook the fact that there are irrationalists who love mankind, and that not all forms of irrationalism engender criminality. But I hold that he who teaches that not reason but love should rule opens up the way for those who rule by hate. (Socrates, I believe, saw something of this when he suggested that mistrust or hatred of argument is related to mistrust or hatred of man)."

"I have learned more from Hayek than from any other living thinker, except perhaps Alfred Tarski - but not even excepting Russell."

"I hold that he who teaches that not reason but love should rule opens up the way for those who rule by hate."

"I have spoken to Einstein and he admitted to me that his theory was in fact no different from the one of Parmenides."

"I may be wrong and you may be right, and by an effort, we may get nearer to the truth."

"I personally call the type of government which can be removed without violence 'democracy,' and the other, 'tyranny.'"

"I remained a socialist for several years, even after my rejection of Marxism; and if there could be such a thing as socialism combined with individual liberty, I would be a socialist still. For nothing could be better than living a modest, simple, and free life in an egalitarian society. It took some time before I recognized this as no more than a beautiful dream; that freedom is more important than equality; that the attempt to realize equality endangers freedom; and that, if freedom is lost, there will not even be equality among the unfree."

"I think that there is only one way to science - or to philosophy, for that matter: to meet a problem, to see its beauty and fall in love with it; to get married to it and to live with it happily, till death do ye part - unless you should meet another and even more fascinating problem or unless, indeed, you should obtain a solution. But even if you do obtain a solution, you may then discover, to your delight, the existence of a whole family of enchanting, though perhaps difficult, problem children, for whose welfare you may work, with a purpose, to the end of your days."

"I may illustrate this by two very different examples of human behavior: that of a man who pushes a child into the water with the intention of drowning it; and that of a man who sacrifices his life in an attempt to save the child. Each of these two cases can be explained with equal ease in Freudian and in Adlerian terms. According to Freud the first man suffered from repression (say, of some component of his Oedipus complex), while the second man had achieved sublimation. According to Adler the first man suffered from feelings of inferiority (producing perhaps the need to prove to himself that he dared to commit some crime), and so did the second man (whose need was to prove to himself that he dared to rescue the child). I could not think of any human behavior which could not be interpreted in terms of either theory. It was precisely this fact ? that they always fitted, that they were always confirmed ? which in the eyes of their admirers constituted the strongest argument in favor of these theories. It began to dawn on me that this apparent strength was in fact their weakness."

"I see now more clearly than ever before that even our greatest troubles spring from something that is as admirable and sound as it is dangerous ? from our impatience to better the lot of our fellows. For these troubles are the by-products of what is perhaps the greatest of all moral and spiritual revolutions of history, a movement which began three centuries ago. It is the longing of uncounted unknown men to free themselves and their minds from the tutelage of authority and prejudice. It is their attempt to build up an open society which rejects the absolute authority to preserve, to develop, and to establish traditions, old or new, that measure up to their standards of freedom, of humaneness, and of rational criticism. It is their unwillingness to sit back and leave the entire responsibility for ruling the world to human or superhuman authority, and their readiness to share the burden of responsibility for avoidable suffering, and to work for its avoidance. This revolution has created powers of appalling destructiveness; but they may yet be conquered."

"I wish to make it clear that ?history? in the sense in which most people speak of it simply does not exist; and this is at least one reason why I say that it has no meaning."

"I think so badly of philosophy that I don't like to talk about it. ? I do not want to say anything bad about my dear colleagues, but the profession of teacher of philosophy is a ridiculous one. We don't need a thousand of trained, and badly trained, philosophers ? it is very silly. Actually most of them have nothing to say."

"I would rather find a single causal law than be the king of Persia!"