Karl Popper
There is no history of mankind, there are only many 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.Collection: Power
Science must begin with myths, and with the criticism of myths.Collection: Science
No rational argument will have a rational effect on a man who does not want to adopt a rational attitude.Collection: Attitude
Science may be described as the art of systematic over-simplification.Collection: Science
Our knowledge can only be finite, while our ignorance must necessarily be infinite.Collection: Knowledge
We must plan for freedom, and not only for security, if for no other reason than that only freedom can make security secure.Collection: Freedom
Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology.Collection: Technology
In so far as a scientific statement speaks about reality, it must be falsifiable; and in so far as it is not falsifiable, it does not speak about reality.
Those who promise us paradise on earth never produced anything but a hell.
It is impossible to speak in such a way that you cannot be misunderstood.
Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve.
Good tests kill flawed theories; we remain alive to guess again.
We have become makers of our fate when we have ceased to pose as its prophets.
The growth of knowledge depends entirely upon disagreement.Collection: Growth
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, then the tolerant will be destroyed, and tolerance with them. We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant.Collection: Names
The only way to test a hypothesis is to look for all the information that disagrees with it.Collection: Looks
Ignorance is not a simple lack of knowledge but an active aversion to knowledge, the refusal to know, issuing from cowardice, pride, or laziness of mind.Collection: Ignorance
True ignorance is not the absence of knowledge, but the refusal to acquire it.Collection: Ignorance
The question is not how to get good people to rule; THE QUESTION IS: HOW TO STOP THE POWERFUL from doing as much damage as they can to us.Collection: Powerful
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.Collection: Tolerance
If you can't say it simply and clearly, keep quiet, and keep working on it till you can.Collection: Quiet
You cannot have a rational discussion with a man who prefers shooting you to being convinced by you.Collection: Men
Optimism is a duty. The future is open. It is not predetermined. No one can predict it, except by chance. We all contribute to determining it by what we do. We are all equally responsible for its success.Collection: Optimism
The defence of democracy must consist in making anti-democratic experiences too costly for those who try them; much more costly than a democratic compromiseCollection: Democracy
I personally call the type of government which can be removed without violence 'democracy,' and the other, 'tyranny.'.Collection: Freedom
It can't happen here is always wrong: a dictatorship can happen anywhere.Collection: Dictatorship
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-à-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.Collection: Philosophy
Every solution of a problem raises new unsolved problems.Collection: Obstacles
The survival value of intelligence is that it allows us to extinct a bad idea, before the idea extincts us.Collection: Ideas
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.Collection: Beautiful
We do not know. We can only guess.Collection: Objectivity
All life is problem solvingCollection: Inspiring
The best thing that can happen to a human being us to find a problem, to fall in love with that problem, and to live trying to solve that problem, unless another problem even more lovable appears.Collection: Falling In Love
A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice.Collection: Thinking
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.Collection: Political
Rationalism is an attitude of readiness to listen to contrary arguments and to learn from experience... of admitting that "I may be wrong and you may be right and, by an effort, we may get nearer the truth."Collection: Attitude
Thus science must begin with myths, and with the criticism of myths; neither with the collection of observations, nor with the invention of experiments, but with the critical discussion of myths, and of magical techniques and practices.Collection: Science
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.Collection: Spring
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.Collection: Beautiful
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.Collection: Men
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.Collection: Thinking
Science is perhaps the only human activity in which errors are systematically criticized and, in time, corrected.Collection: Science
What really makes science grow is new ideas, including false ideas.Collection: Ideas
We never know what we are talking about.Collection: Math
Reason like science, grows by way of mutual criticism; the only possible way of planning its growth is to develop those institutions that safeguard. the freedom of thoughtCollection: Growth
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. It obviously endangers the freedom and the objectivity of our discussion if we attack a person instead of attacking an opinion or, more precisely, a theory.Collection: Men
Historically speaking all - or very nearly all - scientific theories originate from myths.Collection: Theory
The metaphysical doctrine of determinism simply asserts that all events in this world are fixed, or unalterable, or predetermined. It does not assert that they are known to anybody, or predictable by scientific means. But it asserts that the future is as little changeable as is the past. Everybody knows what we mean when we say that the past cannot be changed. It is in precisely the same sense that the future cannot be changed, according to metaphysical determinism.Collection: Future
It is wrong and dangerous to extol freedom by telling people that they will certainly be all right once they are free. The most we can say of democracy or freedom is that they give our personal abilities a little more influence on our well-being.Collection: People
It is easy to obtain confirmations, or verifications, for nearly every theory-if we look for confirmations. Confirmations should count only if they are the result of risky predictions... A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice. Every genuine test of a theory is an attempt to falsify it, or refute it.Collection: Science