Karl Popper Quotes

We seldom find any person of good sense, except those who share our opinions.

Never presume that just because you disagree with an idea that you must be correct.

I'm not staid and unbiased here. I have certain biases I want to convey, and if you disagree, that's fine.

Trust and belief are two prime considerations. You must not allow yourself to be opinionated.

Belief is a very peculiar thing: we tend to put more store in a belief we like than a fact we hate.

Be able to notice all the confusion between fact and opinion that appears in the news.

Every man has a right to his opinion, but no man has the right to be wrong in his facts.

The University is not engaged in making ideas safe for students. It is engaged in making students safe for ideas. Thus it permits the freest expression of views before students, trusting to their good sense in passing judgment on these views. Only in this way can it best serve American democracy.

If a book be false in its facts, disprove them; if false in its reasoning, refute it. But for God's sake, let us freely hear both sides if we choose.

Values are faithfully applied to the facts before us, while ideology overrides whatever facts call theory into question.

We're all biased, right, in many different ways - politically, religiously, ideologically, the way our family raised us - and that's fine. Nobody wants to live in a world where everybody thinks exactly the same. The key, though, is to try to figure out where your biases are holding you back from solving problems.

The more educated we are, the less we are prepared to tolerate views contrary to our own.

The more you think you know, the more closed-minded you'll be.

If you're always in the company of people who agree with you, you're going to think of people who don't agree with you as venal or stupid. I constantly tell my students that if they're in the company of people who always say "amen" to what you say, find other company. And that is the source of illiberalism, when you are unable to listen to someone who thinks differently. That's when democracies are in trouble.

The greatest obstacle to discovering the truth is being convinced that you already know it.

Opinion is the death of knowledge.

Above all, the ability to feel the force of an argument apart from the substance it deals with is the strongest weapon against prejudice.

The human mind can hardly remain entirely free from bias, and decisive opinions are often formed before a thorough examination of a subject from all its aspects has been made.

The tolerance of the skeptic… accepts the most diverse and indeed the most contradictory opinions, and keeps all his suspicions for the “dogmatist.”

We must love them both, those whose opinions we share and those whose opinions we reject, for both have labored in the search for truth, and both have helped us in finding it.

Don't hold strong opinions about things you don't truly understand.

He who knows only his own side of the case (argument) knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion

Interest blinds some people, and enlightens others.

Writers always sound insufferably smug when they sit back and assert that their job is only to ask questions and not to answer them. But, in good part, it is true. And once you become committed to one particular answer, your freedom to ask new questions is seriously impaired.

Most often people seek in life occasions for persisting in their opinions rather than for educating themselves.