Famous quotes

Quotes by famous people, credited to who said them. Your own quotes must not match any of these. More are added all the time. 1,158,269 quotes Who coined it · How we decide

English Italiano Polski עברית Français Português فارسی Español 中文 Русский Deutsch العربية हिन्दी 日本語 Ελληνικά Latina

Karl Popper

99 quotes

“Always remember that it is impossible to speak in such a way that you cannot be misunderstood: there will always be some who misunderstand you.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“One of the ideas I had discussed in The Poverty of Historicism was the influence of a prediction upon the event predicted. I had called this the "Oedipus effect", because the oracle played a most important role in the sequence of events which led to the fulfilment of its prophecy. ... For a time I thought that the existence of the Oedipus effect distinguished the social from the natural sciences. But in biology, too—even in molecular biology—expectations often play a role in bringing about what has been expected.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Darwinism is not a testable scientific theory, but a metaphysical research program.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“As a rule, begin my lectures on Scientific Method by telling my students that scientific method does not exist. ...having been ...the one and only professor of this non-existent subject within the British Commonwealth.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“[S]ubject matters in general do not exist. There are no subject matters; no branches of learning—or, rather, of inquiry: there are only problems, and the urge to solve them.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“[E]ven serious students are misled by the myth of the subject.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Scientific Method... [is] even less existent than some other non-existent subjects.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Plato, Aristotle, Bacon and Descartes, as well... successors... [e.g.,] John Stuart Mill, believed that there existed a method of finding scientific truth. ...[L]ater ...slightly more sceptical ...methodologists ...believed that there existed a method, if not of finding a true theory, then ...of ascertaining whether ...some ...hypothesis was true; or (even more sceptical) whether some ... hypothesis was ...'probable' ...”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I assert (1) There is no method of discovering a scientific theory. (2) There is no method of ascertaining the truth [i.e., verification] of a scientific hypothesis... (3) There is no method of ascertaining whether a hypothesis is 'probable, in the sense of the probability calculus.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I am a rationalist. ...I mean ...[I] wish... to understand the world, and to learn by arguing with others. (...I do not say a rationalist holds the mistaken theory that men are... rational.)”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“By 'arguing...' I mean... criticizing... inviting... criticism; and trying to learn from it.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“[[Argument|[A]rgument]] is a... form of the art of fighting—with words... inspired by... getting nearer to... truth...”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Diversity makes critical argument fruitful. ...[P]artners in an argument must share ...the wish to know, and the readiness to learn from the other ...by severely criticizing his views... and hearing... [the] reply. ...the so-called method of science consists in this kind of criticism.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Scientific theories are distinguished from myths... in being criticizable, and... open to modifications... They can be neither verified nor probabilified.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“[T]he history of mankind could... be described as a history of outbreaks of fashionable philosophical and religious maladies. These... have... one serious function... evoking criticism.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I... believe in the rationalist tradition of a commonwealth of learning, and in the urgent need to preserve this tradition.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“The doctrine that there is as much science in a subject as... mathematics in it, or as much... measurement or 'precision' in it, rests upon... misunderstanding.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Never aim at more precision than... required by the problem...”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I have no faith in precision: ...simplicity and clarity are values in themselves, but not... [of] precision or exactness...”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I do not believe in what is often called... 'exact '... [or] in definitions... [they] do not... add to exactness... I especially dislike pretentious terminology and... pseudo-exactness concerned with it.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“What can be said can and should always be said more and more simply and clearly.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I disbelieve in specialization and... experts. ...[P]aying too much respect to the specialist ...[is] destroying the commonwealth of learning, the rationalist tradition, and science ...”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“[T]here is only one way to science—or to philosophy... 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... more fascinating problem, or... obtain a solution. But even if you do... you may... discover, to your delight, the... a whole family of enchanting... perhaps difficult problem children for whose welfare you may work, with a purpose, to the end of your days.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“All things living are in search of a better world.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“The belief in a political Utopia is especially dangerous. This is possibly connected with the fact that the search for a better world, like the investigation of our environment, is (if I am correct) one of the oldest and most important of all the instincts.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Our aim as scientists is objective truth; more truth, more interesting truth, more intelligible truth. We cannot reasonably aim at certainty. Once we realize that human knowledge is fallible, we realize also that we can never be completely certain that we have not made a mistake.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“There are uncertain truths — even true statements that we may take to be false — but there are no uncertain certainties. Since we can never know anything for sure, it is simply not worth searching for certainty; but it is well worth searching for truth; and we do this chiefly by searching for mistakes, so that we have to correct them.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Why do I think that we, the intellectuals, are able to help? Simply because we, the intellectuals, have done the most terrible harm for thousands of years. Mass murder in the name of an idea, a doctrine, a theory, a religion — that is all our doing, our invention: the invention of the intellectuals. If only we would stop setting man against man — often with the best intentions — much would be gained. Nobody can say that it is impossible for us to stop doing this.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“The answer to this problem is: as implied by Hume, we certainly are not justified in reasoning from an instance to the truth of the corresponding law. But to this negative result a second result, equally negative, may be added: we are justified in reasoning from a counterinstance to the falsity of the corresponding universal law (that is, of any law of which it is a counterinstance). Or in other words, from a purely logical point of view, the acceptance of one counterinstance to 'All swans are white' implies the falsity of the law 'All swans are white' - that law, that is, whose counterinstance we accepted. Induction is logically invalid; but refutation or falsification is a logically valid way of arguing from a single counterinstance to - or, rather, against - the corresponding law.This shows that I continue to agree with Hume's negative logical result; but I extend it.This logical situation is completely independent of any question of whether we would, in practice, accept a single counterinstance - for example, a solitary black swan - in refutation of a so far highly successful law. I do not suggest that we would necessarily be so easily satisfied; we might well suspect that the black specimen before us was not a swan.”
Karl Popper (1902–1994) first seen 1953 wikiquote, CC BY-SA 4.0 source
Recorded in: The Problem of Induction" (1953, 1974)
“Before we as individuals are even conscious of our existence we have been profoundly influenced for a considerable time (since before birth) by our relationship to other individuals who have complicated histories, and are members of a society which has an infinitely more complicated and longer history than they do (and are members of it at a particular time and place in that history); and by the time we are able to make conscious choices we are already making use of categories in a language which has reached a particular degree of development through the lives of countless generations of human beings before us. . . . We are social creatures to the inmost centre of our being. The notion that one can begin anything at all from scratch, free from the past, or unindebted to others, could not conceivably be more wrong.”
Karl Popper (1902–1994) first seen 1973 wikiquote, CC BY-SA 4.0 source
Recorded in: As quoted in Popper (1973) by Bryan Magee
“When I speak of reason or rationalism, all I mean is the conviction that we can learn through criticism of our mistakes and errors, especially through criticism by others, and eventually also through self-criticism. A rationalist is simply someone for whom it is more important to learn than to be proved right; someone who is willing to learn from others — not by simply taking over another's opinions, but by gladly allowing others to criticize his ideas and by gladly criticizing the ideas of others. The emphasis here is on the idea of criticism or, to be more precise, critical discussion. The genuine rationalist does not think that he or anyone else is in possession of the truth; nor does he think that mere criticism as such helps us achieve new ideas. But he does think that, in the sphere of ideas, only critical discussion can help us sort the wheat from the chaff. He is well aware that acceptance or rejection of an idea is never a purely rational matter; but he thinks that only critical discussion can give us the maturity to see an idea from more and more sides and to make a correct judgement of it.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
Recorded in: On Freedom" in All Life is Problem Solving (1999)
“A principle of induction would be a statement with the help of which we could put inductive inferences into a logically acceptable form. In the eyes of the upholders of inductive logic, a principle of induction is of supreme importance for scientific method: "... this principle", says Reichenbach, "determines the truth of scientific theories. To eliminate it from science would mean nothing less than to deprive science of the power to decide the truth or falsity of its theories. Without it, clearly, science would no longer have the right to distinguish its theories from the fanciful and arbitrary creations of the poet's mind." Now this principle of induction cannot be a purely logical truth like a tautology or an analytic statement. Indeed, if there were such a thing as a purely logical principle of induction, there would be no problem of induction; for in this case, all inductive inferences would have to be regarded as purely logical or tautological transformations, just like inferences in inductive logic. Thus the principle of induction must be a synthetic statement; that is, a statement whose negation is not self-contradictory but logically possible. So the question arises why such a principle should be accepted at all, and how we can justify its acceptance on rational grounds.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“If in this book harsh words are spoken about some of the greatest among the intellectual leaders of mankind, my motive is not, I hope, the wish to belittle them. It springs rather from my conviction that, if our civilization is to survive, we must break with the habit of deference to great men. Great men may make great mistakes; and as the book tries to show, some of the greatest leaders of the past supported the perennial attack on freedom and reason. Their influence, too rarely challenged, continues to mislead those on whose defence civilization depends, and to divide them. The responsibility of this tragic and possibly fatal division becomes ours if we hesitate to be outspoken in our criticism of what admittedly is a part of our intellectual heritage. By reluctance to criticize some of it, we may help to destroy it all.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“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.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“This book raises issues that might not be apparent from the table of contents. It sketches some of the difficulties faced by our civilization — a civilization which might be perhaps described as aiming at humanness and reasonableness, at equality and freedom; a civilization which is still in its infancy, as it were, and which continues to grow in spite of the fact that it has been so often betrayed by so many of the intellectual leaders of mankind. It attempts to show that this civilization has not yet fully recovered from the shock of its birth — the transition from the tribal or "enclosed society," with its submission to magical forces, to the 'open society' which sets free the critical powers of man. It attempts to show that the shock of this transition is one of the factors that have made possible the rise of those reactionary movements which have tried, and still try, to overthrow civilization and to return to tribalism.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“What a monument of human smallness is this idea of the philosopher king. What a contrast between it and the simplicity of humaneness of Socrates, who warned the statesmen against the danger of being dazzled by his own power, excellence, and wisdom, and who tried to teach him what matters most — that we are all frail human beings. What a decline from this world of irony and reason and truthfulness down to Plato's kingdom of the sage whose magical powers raise him high above ordinary men; although not quite high enough to forgo the use of lies, or to neglect the sorry trade of every shaman — the selling of spells, of breeding spells, in exchange for power over his fellow-men.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“In speaking of sociological laws or natural laws of social life I have in mind such laws as are formulated by modern economic theories, for instance, the theory of international trade, or the theory of the trade cycle. These and other important sociological laws are connected with the functioning of social institutions. These laws play a role in our social life corresponding to the role played in mechanical engineering by, say, the principle of the lever. For institutions, like levers, are needed if we want to achieve anything which goes beyond the power of our muscles. Like machines, institutions multiply our power for good or evil. Like machines, they need intelligent supervision by someone who understands their way of functioning and, most of all, their purpose, since we cannot build them so that they work entirely automatically.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“The so-called paradox of freedom is the argument that freedom in the sense of absence of any constraining control must lead to very great restraint, since it makes the bully free to enslave the meek. The idea is, in a slightly different form, and with very different tendency, clearly expressed in Plato. Less well known is the paradox of tolerance: Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them. — In this formulation, I do not imply, for instance, that we should always suppress the utterance of intolerant philosophies; as long as we can counter them by rational argument and keep them in check by public opinion, suppression would certainly be unwise. But we should claim the right to suppress them if necessary even by force; for it may easily turn out that they are not prepared to meet us on the level of rational argument, but begin by denouncing all argument; they may forbid their followers to listen to rational argument, because it is deceptive, and teach them to answer arguments by the use of their fists or pistols. We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant. We should claim that any movement preaching intolerance places itself outside the law, and we should consider incitement to intolerance and persecution as criminal, in the same way as we should consider incitement to murder, or to kidnapping, or to the revival of the slave trade, as criminal.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Although my own position is, I believe, clearly enough implied in the text, I may perhaps briefly formulate what seems to me the most important principles of humanitarian and equalitarian ethics. (1) Tolerance towards all who are not intolerant and who do not propagate intolerance. ... This implies, especially, that the moral decisions of others should be treated with respect, as long as such decisions do not conflict with the principle of tolerance. (2) The recognition that all moral urgency has its basis in the urgency of suffering or pain. I suggest, for this reason, to replace the utilitarian formula 'Aim at the greatest amount of happiness for the greatest number', or briefly, 'Maximize happiness' by the formula 'The least amount of avoidable suffering for all', or briefly, 'Minimize suffering'. Such a simple formula can, I believe, be made one of the fundamental principles (admittedly not the only one) of public policy. (The principle 'Maximize happiness', in contrast, seems to be apt to produce a benevolent dictatorship.) We should realize that from the moral point of view suffering and happiness must not be treated as symmetrical; that is to say, the promotion of happiness is in any case much less urgent than the rendering of help to those who suffer, and the attempt to prevent suffering. (The latter task has little to do with 'matters of taste', the former much.)”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I believe that there is, from the ethical point of view, no symmetry between suffering and happiness, or between pain and pleasure. Both the greatest happiness principle of the Utilitarians and Kant's principle 'Promote other people's happiness ..' seem to me (at least in their formulations) wrong on this point which, however, is not completely decidable by rational argument. (For the irrational aspect of ethical beliefs, see note 11 to the present chapter, and for the rational aspect, sections II and especially III of chapter 24). In my opinion (cp. note 6 (2) to chapter 5) human suffering makes a direct moral appeal, namely, the appeal for help, while there is no similar call to increase the happiness of a man who is doing well anyway. (A further criticism of the Utilitarian formula 'Maximize pleasure' is that it assumes, in principle, a continuous pleasure-pain scale which allows us to treat degrees of pain as negative degrees of pleasure. But, from the moral point of view, pain cannot be outweighed by pleasure, and especially not one man's pain by another man's pleasure. Instead of the greatest happiness for the greatest number, one should demand, more modestly, the least amount of avoidable suffering for all; and further, that unavoidable suffering—such as hunger in times of an unavoidable shortage of food—should be distributed as equally as possible.)”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“In previous chapters I have mentioned moral positivism (especially that of Hegel), the theory that there is no moral standard but the one which exists ; that what is, is reasonable and good ; and therefore, that might is right. The practical aspect of this theory is this. A moral criticism of the existing state of affairs is impossible, since this state itself determines the moral standard of things. Now the historicist moral theory we are considering is nothing but another form of moral positivism. For it holds that coming might is right. The future is here substituted for the present,—that is all. And the practical aspect of the theory is this. A moral criticism of the coming state of affairs is impossible, since this state determines the moral standard of things. [...] Marx, I assert, would not seriously have defended moral positivism in the form of moral futurism if he had seen that it implies the recognition of future might as right. But there are others who do not possess his passionate love of humanity, who are moral futurists just because of these implications, i.e. opportunists wishing to be on the winning side. Moral futurism is widespread to-day.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“There is no history of mankind, there is only an indefinite number of histories of all kinds of aspects of human life. And one of these is the history of political power. This is elevated into the history of the world. But this, I hold, is an offence against every decent conception of mankind. It is hardly better than to treat the history of embezzlement or of robbery or of poisoning as the history of mankind. For the history of power politics is nothing but the history of international crime and mass murder (including it is true, some of the attempts to suppress them). This history is taught in schools, and some of the greatest criminals are extolled as heroes.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Not only do I hate violence, but I firmly believe that the fight against it is not hopeless. I realize that the task is difficult. I realize that, only too often in the course of history, it has happened that what appeared at first to be a great success in the fight against violence was followed by a defeat. I do not overlook the fact that the new age of violence which was opened by the two World wars is by no means at an end. Nazism and Fascism are thoroughly beaten, but I must admit that their defeat does not mean that barbarism and brutality have been defeated. On the contrary, it is no use closing our eyes to the fact that these hateful ideas achieved something like a victory in defeat. I have to admit that Hitler succeeded in degrading the moral standards of our Western world, and that in the world of today there is more violence and brutal force than would have been tolerated even in the decade after the first World war. And we must face the possibility that our civilization may ultimately be destroyed by those new weapons which Hitlerism wished upon us, perhaps even within the first decade after the second World war; for no doubt the spirit of Hitlerism won its greatest victory over us when, after its defeat, we used the weapons which the threat of Nazism had induced us to develop.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“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.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“It is wrong to think that belief in freedom always leads to victory; we must always be prepared for it to lead to defeat. If we choose freedom, then we must be prepared to perish along with it. Poland fought for freedom as no other country did. The Czech nation was prepared to fight for its freedom in 1938; it was not lack of courage that sealed its fate. The Hungarian Revolution of 1956 — the work of young people with nothing to lose but their chains — triumphed and then ended in failure. ... Democracy and freedom do not guarantee the millennium. No, we do not choose political freedom because it promises us this or that. We choose it because it makes possible the only dignified form of human coexistence, the only form in which we can be fully responsible for ourselves. Whether we realize its possibilities depends on all kinds of things — and above all on ourselves.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“What we should do, I suggest, is to give up the idea of ultimate sources of knowledge, and admit that all knowledge is human; that it is mixed with our errors, our prejudices, our dreams, and our hopes; that all we can do is to grope for truth even though it be beyond our reach. We may admit that our groping is often inspired, but we must be on our guard against the belief, however deeply felt, that our inspiration carries any authority, divine or otherwise. If we thus admit that there is no authority beyond the reach of criticism to be found within the whole province of our knowledge, however far it may have penetrated into the unknown, then we can retain, without danger, the idea that truth is beyond human authority. And we must retain it. For without this idea there can be no objective standards of inquiry; no criticism of our conjectures; no groping for the unknown; no quest for knowledge.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“Put in a nut-shell, my thesis amounts to this. The repeated attempts made by Rudolf Carnap to show that the demarcation between science and metaphysics coincides with that between sense and nonsense have failed. The reason is that the positivistic concept of 'meaning' or 'sense' (or of verifiability, or of inductive confirmability, etc.) is inappropriate for achieving this demarcation — simply because metaphysics need not be meaningless even though it is not science. In all its variations demarcation by meaninglessness has tended to be at the same time too narrow and too wide: as against all intentions and all claims, it has tended to exclude scientific theories as meaningless, while failing to exclude even that part of metaphysics which is known as 'rational theology'.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“I may illustrate this by two very different examples of human behaviour: 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 behaviour 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 favour of these theories. It began to dawn on me that this apparent strength was in fact their weakness.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source
“'[S]cientific knowledge' always remained sheer guesswork... controlled by criticism and experiment. ...[T]his assumption is sufficient for solving the problem of induction—called by Kant 'the problem of Hume'— without sacrificing empiricism...[i.e.,] without adopting a principle of induction and ascribing to it a priori validity. For guesses are not 'induced from observations' (although they may ...be suggested ...by observations). This ... allows us to accept ...(...without Russell's limits of empiricism) Hume's logical criticism of induction and to give up ...an inductive logic, for certainty, and even for probability, while continuing ...scientific search for truth.”
Karl Popper (1902–1994) said by 1994 at the latest wikiquote, CC BY-SA 4.0 source