Karl Popper Quotes

No matter how many instances of white swans we may have observed, this does not justify the conclusion that all swans are white.

I personally call the type of government which can be removed without violence 'democracy,' and the other, 'tyranny.'.

A theory that explains everything, explains nothing

The growth of knowledge depends entirely upon disagreement.

It can't happen here is always wrong: a dictatorship can happen anywhere.

Genuine philosophical problems are always rooted outside philosophy and they die if these roots decay.

If you can't say it simply and clearly, keep quiet, and keep working on it till you can.

It is not possible to write clearly enough to avoid being misrepresented by people who are sufficiently determined to do so.

Historically speaking all - or very nearly all - scientific theories originate from myths.

No number of sightings of white swans can prove the theory that all swans are white. The sighting of just one black one may disprove it.

We do not know. We can only guess.

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.

Now this principle of induction cannot be a purely logical truth like a tautology or an analytic statement ...

No book can ever be finished. While working on it we learn just enough to find it immature the moment we turn away from it

I have spoken to Einstein and he admitted to me that his theory was in fact no different from the one of Parmenides.

[To] interpret Parmenides as a Kant before Kant ... this is exactly what we must do.

Science must begin with myths, and with the criticism of myths.

It is part of my thesis that all our knowledge grows only through the correcting of our mistakes.

It is wrong to ask who will rule. The ability to vote a bad government out of office is enough. That is democracy.

The moral decisions of others should be treated with respect, as long as such decisions do not conflict with the principle of tolerance.

The future is always present, as a promise, a lure and a temptation.

There is no reason to believe that a definition necessarily determines the ontological status of the term defined.)

Science is perhaps the only human activity in which errors are systematically criticized and, in time, corrected.

Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology.

No rational argument will have a rational effect on a man who does not want to adopt a rational attitude.

The only way to test a hypothesis is to look for all the information that disagrees with it.

Our greatest troubles spring from something that is as admirable as it is dangerous ... our impatience to better the lot of our fellows.

We never know what we are talking about.

Our aim must be to make our successive mistakes as quickly as possible. To speed up evolution.

Science may be described as the art of systematic oversimplification.

It must be possible for an empirical system to be refuted by experience.

The initial stage, the act of conceiving or inventing a theory, seems to me neither to call for logical analysis nor to be susceptible of it.

It is impossible to speak in such a way that you cannot be misunderstood.

The attempt to make heaven on earth invariably produces hell.

True ignorance is not the absence of knowledge, but the refusal to acquire it.

The history of science is everywhere speculative. It is a marvelous hiatory. It makes you proud to be a human being.

No particular theory may ever be regarded as absolutely certain ... No scientific theory is sacrosanct ...

Contrary to the outstanding work of art, outstanding theory is susceptible to improvements.

While differing widely in the various little bits we know, in our infinite ignorance we are all equal.

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.

Our belief in any particular natural law cannot have a safer basis than our unsuccessful critical attempts to refute it.

The most we can say of democracy or freedom is that they give our personal abilities a little more influence on our well-being.

We have become makers of our fate when we have ceased to pose as its prophets.

If we wish our civilization to survive we must break with the habit of deference to great men.

Science is most significant as one of the greatest spiritual adventures that man has yet known.

I have come to the conclusion that Darwinism is not a testable scientific theory, but a metaphysical research programme ...

Definitions ... are never really needed, and rarely of any use

A theory is just a mathematical model to describe the observations.

We must plan for freedom, and not only for security, if for no other reason than only freedom can make security more secure.

I would rather find a single causal law than be the king of Persia!

The quest for precision is analogous to the quest for certainty, and both should be abandoned.

I may be wrong and you may be right, and by an effort, we may get nearer to the truth

We hate the very idea that our own ideas may be mistaken, so we cling dogmatically to our conjectures.

I have learned more from Hayek than from any other living thinker, except perhaps Alfred Tarski - but not even excepting Russell.

Good tests kill flawed theories; we remain alive to guess again.

Our knowledge can only be finite, while our ignorance must necessarily be infinite.

Plato felt that a complete reconstruction of society's political program was needed.

All nationalism or racialism is evil, and Jewish nationalism is no exception.

Those who promise us paradise on earth never produced anything but a hell.

It seems to me certain that more people are killed out of righteous stupidity than out of wickedness.

You cannot have a rational discussion with a man who prefers shooting you to being convinced by you.

If you know that things are bound to happen whatever you do, then you may feel free to give up the fight against them.

In my view, aiming at simplicity and lucidity is a moral duty of all intellectuals: lack of clarity is a sin, and pretentiousness is a crime.

All things living are in search of a better world .

Every solution of a problem raises new unsolved problems.

Every genuine test of a theory is an attempt to falsify it, or to refute it.

There is no history, only histories.

Every discovery contains an irrational element or a creative intuition.

The survival value of intelligence is that it allows us to extinct a bad idea, before the idea extincts us.

Better our hypotheses die for our errors than ourselves.

There is no pure, disinterested, theory-free observation,