Quotes from Karl Popper

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.

The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know; our knowledge of our ignorance. For this indeed, is the main source of our ignorance - the fact that our knowledge can be only finite, while our ignorance must necessarily be infinite.

The aim of argument, or of discussion, should not be victory but progress.

We do not choose political freedom because it promises us this or that. We choose it because it makes possible the only dignified form of human coexistence, the only form in which we can be fully responsible for ourselves. Whether we realize its possibilities depends on all kinds of things — and above all on ourselves.

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.

The point is that, whenever we propose a solution to a problem, we ought to try as hard as we can to overthrow our solution, rather than defend it. Few of us, unfortunately, practice this precept; but other people, fortunately, will supply the criticism for us if we fail to supply it ourselves.

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.—In

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

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.

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

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

A theory which is not refutable by any conceivable event is nonscientific. Irrefutability is not a virtue of a theory (as people often think) but a vice.

The future depends on ourselves, and we do not depend on any historical necessity.

The Utopian attempt to realize an ideal state, using a blueprint of society as a whole, is one which demands a strong centralized rule of a few, and which is therefore likely to lead to a dictatorship.

Learning to read, and to a lesser degree, to write, are of course the major events in one's intellectual development. There is nothing to compare with it, since very few people (Helen Keller is the great exception) can remember what it meant for them to learn to speak.

a rational analysis of the consequences of a decision does not make the decision rational; the consequences do not determine our decision; it is always we who decide.

The method of learning by trial and error—of learning from our mistakes—seems to be fundamentally the same whether it is practised by lower or by higher animals, by chimpanzees or by men of science.

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.

This false epistemology, however, has also led to disastrous consequences. The theory that truth is manifest—that it is there for everyone to see, if only he wants to see it—this theory is the basis of almost every kind of fanaticism. For only the most depraved wickedness can refuse to see the manifest truth; only those who have reason to fear truth conspire to suppress it.

Great men may make great mistakes;

if God had wanted to put everything into the world 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.

We must regard all laws or theories as hypothetical or conjectural; that is, as guesses.

As indicated by our example, methodological nominalism is nowadays fairly generally accepted in the natural sciences. The problems of the social sciences, on the other hand, are still for the most part treated by essentialist methods. This is, in my opinion, one of the main reasons for their backwardness.

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