Quotessence
Home / Authors / Karl Popper Books
Karl Popper

Karl Popper Books

Philosopher

Related Quotes

“Neither nature nor history can tell us what we ought to do. Facts, whether those of nature or those of history, cannot make the decision for us, they cannot determine the ends we are going to choose. It is we who introduce purpose and meaning into nature and into history. Men are not equal; but we can decide to fight for equality. Human institutions such as the state are not rational, but we can decide to fight to make them more rational. We ourselves and our ordinary language are, on the whole, emotional rather than rational; but we can try to become a little more rational, and we can train ourselves to use our language as an instrument not of self-expression (as our romantic educationists would say) but of rational communication. History itself I mean the history of power politics, of course, not the non-existent story of the development of mankind has no end nor meaning, but we can decide to give it both. We can make it our fight for the open society and against its antagonists (who, when in a corner, always protest their humanitarian sentiments, in accordance with Pareto's advice) and we can interpret it accordingly. Ultimately, we may say the same about the 'meaning of life'. It is up to us to decide what shall be our purpose in life, to determine our ends. This dualism of facts and decisions is, I believe, fundamental. Facts as such have no meaning; they can gain it only through our decisions. Historicism is only one of many attempts to get over this dualism; it is born of fear, for it shrinks from realizing that we bear the ultimate responsibility even for the standards we choose. But such an attempt seems to me to represent precisely what is usually described as superstition. For it assumes that we can reap where we have not sown; it tries to persuade us that if we merely fall into step with history everything will and must go right, and that no fundamental decision on our part is required; it tries to shift our responsibility on to history, and thereby on to the play of demoniac powers beyond ourselves; it tries to base our actions upon the hidden intentions of these powers, which can be revealed to us only in mystical inspirations and intuitions; and it thus puts these actions and decisions on the moral level of one who, inspired by horoscopes and dreams, chooses his lucky number in a lottery.”

PhilosophyHuman NatureAspirationPragmatismMoral Obligation
Book:The Open society & its enemies: Vol 2 Hegel & Marx
Create image

“It is clear that spiritual naturalism can be used to defend any ‘positive’, i.e. existing, norm. For it can always be argued that these norms would not be in force if they did not express some traits of human nature. [...] In fact, this form of naturalism is so wide and so vague that it may be used to defend anything. There is nothing that has ever occurred to man which could not be claimed to be ‘natural’; for if it were not in his nature, how could it have occurred to him? Looking back at this brief survey, we may perhaps discern two main tendencies which stand in the way of adopting a critical dualism. The first is a general tendency towards monism, that is to say, towards the reduction of norms to facts. The second lies deeper, and it possibly forms the background of the first. It is based upon our fear of admitting to ourselves that the responsibility for our ethical decisions is entirely ours and cannot be shifted to anybody else; neither to God, nor to nature, nor to society, nor to history. All these ethical theories attempt to find somebody, or perhaps some argument, to take the burden from us. But we cannot shirk this responsibility. Whatever authority we may accept, it is we who accept it. We only deceive ourselves if we do not realize this simple point.”

ResponsibilityHuman NatureEthicsPolitical PhilosophyMoral PhilosophyNature Vs NurtureMonismAvoiding ResponsibilitySpiritual NaturalismEthical Theories
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“Our dream of heaven cannot be realized on earth. Once we begin to rely upon our reason, and to use our powers of criticism, once we feel the call of personal responsibilities, and with it, the responsibility of helping to advance knowledge, we cannot return to a state of implicit submission to tribal magic. For those who have eaten from the tree of knowledge, paradise is lost. The more we try to return to tribal heroism, the more surely do we arrive at the Inquisition, at the Secret Police, and at a romanticized gangsterism. Beginning with the suppression of reason and truth, we must end with the most brutal and violent destruction of all that is human. There is no return to a harmonious state of nature. If we turn back, then we must go the whole way, we must return to the beasts. It is an issue which we must face squarely, hard though it may be for us to do so. If we dream of a return to our childhood, if we are tempted to rely on others and so be happy, if we turn back from the task of carrying our cross, the cross of humaneness, of reason, of responsibility, if we lose courage and flinch from the strain, then we must try to fortify ourselves with a clear understanding of the simple decision before us. We can return to the beasts. But if we wish to remain human, then there is only one way, the way into the open society. We must go on into the unknown, courageously, using what reason we have, to plan for security and freedom.”

PoliticsFreedomMoralityCivilizationPolitical ScienceUtopianism
Book:The Open Society and Its Enemies
Create image

“Not only poetry but also music in the ordinary sense of the term are to be controlled by a rigid censorship, and both are to be devoted entirely to strengthening the stability of the state by making the young more conscious of class discipline, and thus more ready to serve class interests. Plato even forgets that it is the function of music to make the young more gentle, for he demands such forms of music as will make them braver, i.e. fiercer. (Considering that Plato was an Athenian, his arguments concerning music proper appear to me almost incredible in their superstitious intolerance, especially if compared with a more enlightened contemporary criticism. But even now he has many musicians on his side, possibly because they are flattered by his high opinion of the importance of music, i.e. of its political power. The same is true of educationists, and even more of philosophers, since Plato demands that they should rule.) The political principle that determines the education of the soul, namely, the preservation of the stability of the state, determines also that of the body. The aim is simply that of Sparta.”

MusicCensorshipPlatoTotalitarianismAthensClass WarfareSpartaPlatonismThe RepublicClass Structure
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“The difficulties connected with my criterion of demarcation (D) are important, but must not be exaggerated. It is vague, since it is a methodological rule, and since the demarcation between science and nonscience is vague. But it is more than sharp enough to make a distinction between many physical theories on the one hand, and metaphysical theories, such as psychoanalysis, or Marxism (in its present form), on the other. This is, of course, one of my main theses; and nobody who has not understood it can be said to have understood my theory. The situation with Marxism is, incidentally, very different from that with psychoanalysis. Marxism was once a scientific theory: it predicted that capitalism would lead to increasing misery and, through a more or less mild revolution, to socialism; it predicted that this would happen first in the technically highest developed countries; and it predicted that the technical evolution of the 'means of production' would lead to social, political, and ideological developments, rather than the other way round. 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. Thus one might say that Marxism was once a science, but one which was refuted by some of the facts which happened to clash with its predictions (I have here mentioned just a few of these facts). 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. Psychoanalysis is a very different case. It is an interesting psychological metaphysics (and no doubt there is some truth in it, as there is so often in metaphysical ideas), but it never was a science. There may be lots of people who are Freudian or Adlerian cases: Freud himself was clearly a Freudian case, and Adler an Adlerian case. But what prevents their theories from being scientific in the sense here described is, very simply, that they do not exclude any physically possible human behaviour. Whatever anybody may do is, in principle, explicable in Freudian or Adlerian terms. (Adler's break with Freud was more Adlerian than Freudian, but Freud never looked on it as a refutation of his theory.) The point is very clear. Neither Freud nor Adler excludes any particular person's acting in any particular way, whatever the outward circumstances. Whether a man sacrificed his life to rescue a drowning, child (a case of sublimation) or whether he murdered the child by drowning him (a case of repression) could not possibly be predicted or excluded by Freud's theory; the theory was compatible with everything that could happen—even without any special immunization treatment. Thus while Marxism became non-scientific by its adoption of an immunizing strategy, psychoanalysis was immune to start with, and remained so. In contrast, most physical theories are pretty free of immunizing tactics and highly falsifiable to start with. As a rule, they exclude an infinity of conceivable possibilities.”

RealitySciencePsychologyPossibilityRevolutionDifficultyInfiniteSocialismClarityTreatmentVagueMarxismPsychoanalysisRuleCruelScientific TheoryFreudPointAdlerSigmund FreudFreudianFalsifiableDemarcationAdlerianAlfred AdlerAlfred W AdlerKarl Heinrich MarxKarl Marx Marx Marxism
Author:Karl Popper
Create image

“We see here that Plato recognizes only one ultimate standard, the interest of the state. Everything that furthers it is good and virtuous and just; everything that threatens it is bad and wicked and unjust. Actions that serve it are moral; actions that endanger it, immoral. In other words, Plato’s moral code is strictly utilitarian; it is a code of collectivist or political utilitarianism. The criterion of morality is the interest of the state. Morality is nothing but political hygiene. This is the collectivist, the tribal, the totalitarian theory of morality: ‘Good is what is in the interest of my group; or my tribe; or my state.’ It is easy to see what this morality implied for international relations: that the state itself can never be wrong in any of its actions, as long as it is strong; that the state has the right, not only to do violence to its citizens, should that lead to an increase of strength, but also to attack other states, provided it does so without weakening itself. (This inference, the explicit recognition of the amorality of the state, and consequently the defence of moral nihilism in international relations, was drawn by Hegel.)”

PoliticsNationalismTotalitarianismCollectivismDictatorshipsAmoralityState ViolenceAnti IndividualismAnti Democratic ThoughtState Oppression
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“How does Plato solve the problem of avoiding class war? Had he been a progressivist, he might have hit on the idea of a classless, equalitarian society; for, as we can see for instance from his own parody of Athenian democracy, there were strong equalitarian tendencies at work in Athens. But he was not out to construct a state that might come, but a state that had been—the father of the Spartan state, which was certainly not a classless society. It was a slave state, and accordingly Plato’s best state is based on the most rigid class distinctions. It is a caste state. The problem of avoiding class war is solved, not by abolishing classes, but by giving the ruling class a superiority which cannot be challenged. As in Sparta, the ruling class alone is permitted to carry arms, it alone has any political or other rights, and it alone receives education, i.e. a specialized training in the art of keeping down its human sheep or its human cattle.”

PlatoTotalitarianismClass WarfareEgalitarianismCaste SystemRuling ClassPlatonismSpartans
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“The communism of the ruling caste of his best city can thus be derived from Plato’s fundamental sociological law of change; it is a necessary condition of the political stability which is its fundamental characteristic. But although an important condition, it is not a sufficient one. In order that the ruling class may feel really united, that it should feel like one tribe, i.e. like one big family, pressure from without the class is as necessary as are the ties between the members of the class. This pressure can be secured by emphasizing and widening the gulf between the rulers and the ruled. The stronger the feeling that the ruled are a different and an altogether inferior race, the stronger will be the sense of unity among the rulers. We arrive in this way at the fundamental principle, announced only after some hesitation, that there must be no mingling between the classes.”

PlatoTotalitarianismElitismCaste SystemRuling ClassPlatonism
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“In the present chapter, the doctrine of the chosen people serves only as an illustration. Its value as such can be seen from the fact that its chief characteristics are shared by the two most important modern versions of historicism, whose analysis will form the major part of this book—the historical philosophy of racialism or fascism on the one (the right) hand and the Marxian historical philosophy on the other (the left). For the chosen people racialism substitutes the chosen race (of Gobineau’s choice), selected as the instrument of destiny, ultimately to inherit the earth. Marx’s historical philosophy substitutes for it the chosen class, the instrument for the creation of the classless society, and at the same time, the class destined to inherit the earth. Both theories base their historical forecasts on an interpretation of history which leads to the discovery of a law of its development. In the case of racialism, this is thought of as a kind of natural law; the biological superiority of the blood of the chosen race explains the course of history, past, present, and future; it is nothing but the struggle of races for mastery. In the case of Marx’s philosophy of history, the law is economic; all history has to be interpreted as a struggle of classes for economic supremacy.”

FascismMarxismClass WarfareFar RightFar LeftHistoricismRacialism
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“According to Plato, internal strife, class war, fomented by self-interest and especially material or economic self-interest, is the main force of ‘social dynamics’. The Marxian formula ‘The history of all hitherto existing societies is a history of class struggle’8 fits Plato’s historicism nearly as well as that of Marx. The four most conspicuous periods or ‘landmarks in the history of political degeneration’, and, at the same time, ‘the most important … varieties of existing states’, are described by Plato in the following order. First after the perfect state comes ‘timarchy’ or ‘timocracy’, the rule of the noble who seek honour and fame; secondly, oligarchy, the rule of the rich families; ‘next in order, democracy is born’, the rule of liberty which means lawlessness; and last comes ‘tyranny … the fourth and final sickness of the city’. As can be seen from the last remark, Plato looks upon history, which to him is a history of social decay, as if it were the history of an illness: the patient is society; and, as we shall see later, the statesman ought to be a physician (and vice versa)—a healer, a saviour. [...] We see that Plato aimed at setting out a system of historical periods, governed by a law of evolution; in other words, he aimed at a historicist theory of society. This attempt was revived by Rousseau, and was made fashionable by Comte and Mill, and by Hegel and Marx; but considering the historical evidence then available, Plato’s system of historical periods was just as good as that of any of these modern historicists. (The main difference lies in the evaluation of the course taken by history. While the aristocrat Plato condemned the development he described, these modern authors applauded it, believing as they did in a law of historical progress.) [...] It is important to note that Plato explicitly identified this best and oldest among the existing states with the Dorian constitution of Sparta and Crete, and that these two tribal aristocracies did in fact represent the oldest existing forms of political life within Greece. Most of Plato’s excellent description of their institutions is given in certain parts of his description of the best or perfect state, to which timocracy is so similar. (Through his doctrine of the similarity between Sparta and the perfect state, Plato became one of the most successful propagators of what I should like to call ‘the Great Myth of Sparta’—the perennial and influential myth of the supremacy of the Spartan constitution and way of life.)”

TyrannyPlatoMarxismClass WarfareMarxRousseauPlatonismSocial DecayTimocracy
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“According to Plato, internal strife, class war, fomented by self-interest and especially material or economic self-interest, is the main force of ‘social dynamics’. The Marxian formula ‘The history of all hitherto existing societies is a history of class struggle’ fits Plato’s historicism nearly as well as that of Marx. The four most conspicuous periods or ‘landmarks in the history of political degeneration’, and, at the same time, ‘the most important … varieties of existing states’, are described by Plato in the following order. First after the perfect state comes ‘timarchy’ or ‘timocracy’, the rule of the noble who seek honour and fame; secondly, oligarchy, the rule of the rich families; ‘next in order, democracy is born’, the rule of liberty which means lawlessness; and last comes ‘tyranny … the fourth and final sickness of the city’. As can be seen from the last remark, Plato looks upon history, which to him is a history of social decay, as if it were the history of an illness: the patient is society; and, as we shall see later, the statesman ought to be a physician (and vice versa)—a healer, a saviour. [...] We see that Plato aimed at setting out a system of historical periods, governed by a law of evolution; in other words, he aimed at a historicist theory of society. This attempt was revived by Rousseau, and was made fashionable by Comte and Mill, and by Hegel and Marx; but considering the historical evidence then available, Plato’s system of historical periods was just as good as that of any of these modern historicists. (The main difference lies in the evaluation of the course taken by history. While the aristocrat Plato condemned the development he described, these modern authors applauded it, believing as they did in a law of historical progress.) [...] It is important to note that Plato explicitly identified this best and oldest among the existing states with the Dorian constitution of Sparta and Crete, and that these two tribal aristocracies did in fact represent the oldest existing forms of political life within Greece. Most of Plato’s excellent description of their institutions is given in certain parts of his description of the best or perfect state, to which timocracy is so similar. (Through his doctrine of the similarity between Sparta and the perfect state, Plato became one of the most successful propagators of what I should like to call ‘the Great Myth of Sparta’—the perennial and influential myth of the supremacy of the Spartan constitution and way of life.)”

DemocracyTyrannyPlatoMarxismClass StruggleClass WarfareRousseauPlatonism
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“The internal disunion of human nature, the schism of the soul, leads to the schism of the ruling class. And as with Heraclitus, war, class war, is the father and promoter of all change, and of the history of man, which is nothing but the history of the breakdown of society. We see that Plato’s idealist historicism ultimately rests not upon a spiritual, but upon a biological basis; it rests upon a kind of meta-biology of the race of men. Plato was not only a naturalist who proffered a biological theory of the state, he was also the first to proffer a biological and racial theory of social dynamics, of political history.”

PoliticsRacismPlatoPolitical PhilosophyTotalitarianismAuthoritarianismFar RightPlatonismRacial TheoryIdealist Historicism
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“It is often asserted that, in view of the situation in quantum theory, object and subject can no longer be sharply separated. 1 To use Heitler’s words, the ‘separation of the world into an “objective outside reality”, and “us”, the self-conscious onlookers, can no longer be maintained. Object and subject become inseparable from each other’. 2 This, according to Bohr, is due to ‘the impossibility of any sharp separation between the behaviour of atomic objects and the interaction with the measuring instruments which serve to define the conditions under which the phenomena appear’. 3 Heitler elaborates the point in some detail. ‘One may ask’, he writes, ‘if it is sufficient to carry out a measurement by a self-registering apparatus or whether the presence of an observer is required.’ And he arrives at the conclusion that the self-registering apparatus is insufficient, and that ‘the observer appears, as a necessary part of the whole structure, and in his full capacity as a conscious being’.”

RealityObjectivityQuantum PhysicsKarl Popper
Author:Karl Popper
Create image

“But the approach to truth is not easy. There is only one way towards it, the way through error. Only through our errors can we learn; and only he will learn who is ready to appreciate and even to cherish the errors of others as stepping stones towards truth, and who searches for his own errors: who tries to find them, since only when he has become aware of them can he free himself from them.”

TruthKnowledgeErrorKarl Popper
Book:In Search of a Better World
Create image

“The belief in causality is metaphysical. It is nothing but a typical metaphysical hypostatization of a well-justified methodological rule- the scientist's decision never to abandon his search for laws. The metaphysical belief in causality seems thus more fertile in its various manifestations than any indeterminist physics metaphysics of the kind advocated by Heisenberg. Indeed, we can see that Heisenberg's comments have had a crippling effect on research. Connections which are not far to seek may easily be overlooked if its continually repeated that the search for any such connections is 'meaningless'.”

ScienceQuantum MechanicsCausalityIndeterminism
Book:The Logic of Scientific Discovery
Create image

“At the same time, the reader is led to identify individualism with the views of Thrasymachus, and to think that Plato, in his fight against it, is fighting against all the subversive and nihilistic tendencies of his time. But we should not allow ourselves to be frightened by an individualist bogy such as Thrasymachus (there is a great similarity between his portrait and the modern collectivist bogy of ‘bolshevism’) into accepting another more real and more dangerous because less obvious form of barbarism. For Plato replaces Thrasymachus’ doctrine that the individual’s might is right by the equally barbaric doctrine that right is everything that furthers the stability and the might of the state.”

NationalismIndividualismPolitical PhilosophyTotalitarianismCollectivismPlatonismAnti IndividualismAnti Democratic ThoughtState Oppression
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“From the point of view of totalitarian ethics, from the point of view of collective utility, Plato’s theory of justice is perfectly correct. To keep one’s place is a virtue. It is that civil virtue which corresponds exactly to the military virtue of discipline. And this virtue plays exactly that rôle which ‘justice’ plays in Plato’s system of virtues. For the cogs in the great clockwork of the state can show ‘virtue’ in two ways. First, they must be fit for their task, by virtue of their size, shape, strength, etc.; and secondly, they must be fitted each into its right place and must retain that place. The first type of virtues, fitness for a specific task, will lead to a differentiation, in accordance with the specific task of the cog. Certain cogs will be virtuous, i.e. fit, only if they are (‘by their nature’) large; others if they are strong; and others if they are smooth. But the virtue of keeping to one’s place will be common to all of them; and it will at the same time be a virtue of the whole: that of being properly fitted together—of being in harmony. To this universal virtue Plato gives the name ‘justice’. This procedure is perfectly consistent and it is fully justified from the point of view of totalitarian morality. If the individual is nothing but a cog, then ethics is nothing but the study of how to fit him into the whole.”

OppressionAlienationTotalitarianismCollectivismOrganizational CultureTop DownAnti IndividualismHierarchical SystemsCog In The MachineState Oppression
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“But we must realize that even this tendency to restrict the exploitation of class privileges is a fairly common ingredient of totalitarianism. Totalitarianism is not simply amoral. It is the morality of the closed society—of the group, or of the tribe; it is not individual selfishness, but it is collective selfishness.”

SelfishnessNationalismAltruismTotalitarianismEgoismCollectivismTribalismIdentity PoliticsGroupthinkAnti Individualism
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“This ground-plan, conceived by a great architect, exhibits a fundamental metaphysical dualism in Plato’s thought. [...] In politics, it is the opposition between the one collective, the state, which may attain perfection and autarchy, and the great mass of the people—the many individuals, the particular men who must remain imperfect and dependent, and whose particularity is to be suppressed for the sake of the unity of the state (see the next chapter). And this whole dualist philosophy, I believe, originated from the urgent wish to explain the contrast between the vision of an ideal society, and the hateful actual state of affairs in the social field—the contrast between a stable society, and a society in the process of revolution.”

IdealismPlatoSocial ChangeConservatismPolitical PhilosophyAuthoritarianismCollectivismPlatonismImmutabilityAutarchy
Book:The Open Society and Its Enemies - Volume One: The Spell of Plato
Create image

“Historicism is born of our despair in the rationality and responsibility of our actions. It is a debased hope and a debased faith, an attempt to replace the hope and the faith that springs from our moral enthusiasm and the contempt for success by a certainty that springs from a pseudo-science; a pseudoscience of the stars, or of ‘human nature,’ or of historical destiny.”

HopeHistoryEthical Responsibility
Book:The Open society & its enemies: Vol 2 Hegel & Marx
Create image

“The discovery of instances which confirm a theory means very little if we have not tried, and failed, to discover refutations. For if we are uncritical we shall always find what we want: we shall look for, and find, confirmation, and we shall look away from, and not see, whatever might be dangerous to our pet theories. In this way it is only too easy to obtain what appears to be overwhelming evidence in favour of a theory which, if approached critically, would have been refuted.”

ScienceBiasRefutationFalsifiability
Book:The Poverty of Historicism
Create image

“We all have an unscientific weakness for being always in the right, and this weakness seems to be particularly common among professional and amateur politicians. But the only way to apply something like scientific method in politics is to proceed on the assumption that there can be no political move which has no drawbacks, no undesirable consequences. To look out for these mistakes, to find them, to bring them into the open, to analyse them, and to learn from them, this is what a scientific politician as well as a political scientist must do. Scientific method in politics means that the great art of convincing ourselves that we have not made any mistakes, of ignoring them, of hiding them, and of blaming others from them, is replaced by the greater art of accepting the responsibility for them, of trying to learn from them, and of applying this knowledge so that we may avoid them in future.”

SciencePoliticsOpenness
Book:The Poverty of Historicism
Create image

“Every time we proceed to explain some conjectural law or theory by a new conjectural theory of a higher degree of universality, we are discovering more about the world, trying to penetrate deeper into its secrets. And every time we succeed in falsifying a theory of this kind, we make an important new discovery. For these falsifications are most important. They teach us the unexpected; and they reassure us that, although our theories are made by ourselves, although they are our own inventions, they are none the less genuine assertions about the world; for they can clash with something we never made.”

ScienceKnowledgeObjectivity
Book:Objective Knowledge: An Evolutionary Approach
Create image

“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.”

KnowsIdeasRealityScienceTheoryMistakenMechanicClashQuantum Mechanics
Book:Quantum Theory and the Schism in Physics: From the Postscript to The Logic of Scientific Discovery
Create image

“Is the world ruled by strict laws or not? This question I regard as metaphysical. The laws we find are always hypotheses; which means that they may always be superseded, and that they may possibly be deduced from probability estimates. Yet denying causality would be the same as attempting to persuade the theorist to give up his search; and that such an attempt cannot be backed by anything like a proof.”

WorldGivingMayMeanWould BeLawScienceGiving UpRegardProofStrictProbabilityMetaphysicalMechanicHypothesisAttemptingQuantum MechanicsTheoristsCausalityStrict Laws
Book:The Logic of Scientific Discovery
Create image

“It is not intuitive ease I am after, but rather a point of view which is sufficiently definite to clear up some difficulties, and to be criticized in rational terms. (Bohr's complementarity cannot be so criticized, I fear; it can only be accepted or denounced - perhaps as being ad hoc, or as being irrational, or as being hopelessly vague.)”

ScienceTermViewsClearDifficultyPoint Of ViewAcceptedRationalEaseAdsIrrationalDefiniteVagueMechanicIntuitiveQuantum Mechanics
Book:Quantum Theory and the Schism in Physics: From the Postscript to The Logic of Scientific Discovery
Create image

“If we are uncritical we shall always find what we want: we shall look for, and find, confirmations, and we shall look away from, and not see, whatever might be dangerous to our pet theories. In this way it is only too easy to obtain what appears to be overwhelming evidence in favor of a theory which, if approached critically, would have been refuted.”

IfsWayWantLooksHas BeensMightEasyDangerousTheoryEvidenceFavorsPetOverwhelmingConfirmationRefutation
Book:The Poverty of Historicism
Create image

“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.”

IfsMenWaySaidSeemsWould BeWantedUniverseTermInterestingEventsEvolutionUnexpectedOrganismsTheological
Book:Unended Quest: An Intellectual Autobiography
Create image

“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.”

MeanIdeasGamesWinningInstrumentsPrizeAnticipationUnwillingHazardsGraspingInterpretingRefutationUnjustified
Book:The Logic of Scientific Discovery
Create image

“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).”

MenWayShouldBelieveReasonFactsFormHateI BelieveTeachSawsMankindArgumentHatredRelatedMistrustCriminality
Author:Karl Popper
Create image

“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.”

MenWorldMayReasonDreamEarthPastBeautifulPoliticalHeavenEmotionCitiesAttitudeHellSucceedSpringMiracleFellowsIntentionAppealsDesperateHeavenlyIrrationalFellow ManRomanticismIntoxicationHeaven On EarthRadicalismBeautiful WorldBest Intentions
Book:The Open Society and Its Enemies
Create image

“We know a great deal, but our ignorance is sobering and boundless. With each step forward, with each problem which we solve, we not only discover new and unsolved problems, but we also discover that where we believed that we were standing on firm and safe ground, all things are, in truth, insecure and in a state of flux.”

KnowsStatesProblemDealsStepsIgnoranceSafeStandingAll ThingsSolveFirmInsecureBoundlessSteps ForwardFluxUnsolved Problems
Author:Karl Popper
Create image