Sir Karl Raimund Popper CH FBA FRS (28 July 1902 – 17 September 1994) was an Austrian-British philosopher and professor. He is generally regarded as one of the 20th century's greatest philosophers of science.
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.
The history of science is everywhere speculative. It is a marvelous hiatory. It makes you proud to be a human being.
Good tests kill flawed theories; we remain alive to guess again.
Every discovery contains an irrational element or a creative intuition.
It is often asserted that discussion is only possible between people who have a common language and accept common basic assumptions. I think that this is a mistake. All that is needed is a readiness to learn from one's partner in the discussion, which includes a genuine wish to understand what he intends to say. If this readiness is there, the discussion wrighteous stupidityill be the more fruitful the more the partner's backgrounds differ.
There will be well-testable theories, hardly testable theories, and non-testable theories. Those which are non-testable are of no interest to empirical scientists. They may be described as metaphysical.
There is no history, only histories.
The moral decisions of others should be treated with respect, as long as such decisions do not conflict with the principle of tolerance.
We should realize that, if [Socrates] demanded that the wisest men should rule, he clearly stressed that he did not mean the learned men; in fact, he was skeptical of all professional learnedness, whether it was that of the philosophers or of the learned men of his own generation, the Sophists. The wisdom he meant was of a different kind. It was simply the realization: how little do I know! Those who did not know this, he taught, knew nothing at all. This is the true scientific spirit.
There can be no ultimate statements science: there can be no statements in science which can not be tested, and therefore none which cannot in principle be refuted, by falsifying some of the conclusions which can be deduced from them.
All life is problem solving
Psychologism is, I believe, correct only in so far as it insists upon what may be called 'methodological individualism' as opposed to 'methodological collectivism'; it rightly insists that the 'behaviour' and the 'actions' of collectives, such as states or social groups, must be reduced to the behaviour and to the actions of human individuals. But the belief that the choice of such an individualist method implies the choice of a psychological method is mistaken.
It is clear that everybody interested in science must be interested in world 3 objects. A physical scientist, to start with, may be interested mainly in world 1 objects--say crystals and X-rays. But very soon he must realize how much depends on our interpretation of the facts, that is, on our theories, and so on world 3 objects. Similarly, a historian of science, or a philosopher interested in science must be largely a student of world 3 objects.
[To] interpret Parmenides as a Kant before Kant. . . this is exactly what we must do.
Philosophy is a necessary activity because we, all of us, take a great number of things for granted, and many of these assumptions are of a philosophical character; we act on them in private life, in politics, in our work, and in every other sphere of our lives -- but while some of these assumptions are no doubt true, it is likely, that more are false and some are harmful. So the critical examination of our presuppositions -- which is a philosophical activity -- is morally as well as intellectually important.
It is complete nihilism to propose laying down arms in a world where atom bombs are around. It is very simple: there is no way of achieving peace other than with weapons.
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 thought
Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology.
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.
While differing widely in the various little bits we know, in our infinite ignorance we are all equal.