Quotes from Karl R. Popper

A people ought to fight for the laws of the city as if they were its walls.

El lenguaje produce sus propios problemas, sus propias tensiones, sus propios retos y, por tanto, su propia selección, tanto natural como crítica.

I suggest that the emergence of descriptive language is at the root of the human power of imagination, of human inventiveness, and therefore the emergence of world 3.

The prophetic element in Marx's creed was dominant in the minds of his followers. It swept everything else aside, banishing the power of cool and critical judgement and destroying the belief that by the use of reason we may change the world. All that remained of Marx's teaching was the oracular philosophy of Hegel, which in its Marxist trappings threatens to paralyse the struggle for the open society.

The prolonged use of violence may lead in the end to the loss of freedom, since it is liable to bring about not a dispassionate rule of reason, but the rule of the strong man. A violent revolution which tries to attempt more than the destruction of tyranny is at least as likely to bring about another tyranny as it is likely to achieve its real aims.

The Vienna Circle was empiricist and phenomenalist, Popper was a critical rationalist.

Scientific' Marxism is dead. Its feeling of social responsibility and its love for freedom must survive.

The method of science depends upon our attempts to describe the world with simple theories: theories that are complex may become untestable , even if they happen to be true. Science may be described as the art of systematic over-simplification–the art of discerning what we may with advantage omit.

The old scientific idea of episteme-of absoutely certain, demonstrable knowledge-has proved to be an idol. The demand for scientific objectivity makes it inevitable that every scientific statement must remain tentative for ever. It may indeed be corroborated, but every corroboration is relative to other statements which, again, are tentative. Only in our subjective experiences of conviction, in our subjective faith, can we be 'absolutely certain'.

Moreover, if we could show, on general logical grounds, that the scientific quest is likely to succeed, one could not understand why anything like success has been so rare in the long history of human endeavours to know more about our world.

All political ideals, that of making the people happy is perhaps the most dangerous one. It leads invariably to the attempt to impose our scale of 'higher' values upon others, in order to make them realize what seems to us of greatest importance for their happiness; in order, as it were, to save their souls. It leads to Utopianism and Romanticism. We all feel certain that everybody would be happy in the beautiful, the perfect community of our dreams.

Relativism is one of the many crimes committed by intellectuals. It is a betrayal of reason and of humanity.

Most of us, it seems, have a strong inclination to accept the peculiarities of our social environment as if they were 'natural'.

The reality of time and change seemed to me the crux of realism.

It is our duty to help those who need our help; but it cannot be our duty to make others happy, since this does not depend on us, and since it would only too often mean intruding on the privacy of those towards whom we have such amiable intentions.

Never let yourself be goaded into taking seriously problems about words and their meanings. What must be taken seriously are questions of fact, and assertions about facts: theories and hypotheses; the problems they solve; and the problems they raise.

Society and the individual are thus interdependent. The one owes its existence to the other. Society owes its existence to human nature, and especially to its lack of self-sufficiency; and the individual owes his existence to society, since he is not self-sufficient. But within this relationship of interdependence, the superiority of the state over the individual manifests itself in various ways;

I believe I learned more about the theory of knowledge from my dear omniscient master Adalbert Pösch than from any other of my teachers. None did so much to turn me into a disciple of Socrates. 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.

It has been indicated above that because of its self-sufficiency, the ideal state appears to Plato as the perfect individual, and the individual citizen, accordingly, as an imperfect copy of the state.

The 'conspiracy theory of society' is a typical result of a secularization of a religious superstition. The belief in the Homeric gods whose conspiracies explain the history of the Trojan War is gone. The gods are abandoned. But their place is filled by powerful men or groups - sinister pressure groups whose wickedness is responsible for all the evils we suffer from - such as the Learned Elders of Zion, or the monopolists, or the capitalists, or the imperialists.

I conjecture that the origin of life and the origin of problems coincide.

There is an almost universal tendency, perhaps an inborn tendency, to suspect the good faith of a man who holds opinions that differ from our own opinions.

Science may be described as the art of systematic over-simplification — the art of discerning what we may with advantage omit.

Those among us who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game.