I think that we shall have to get accustomed to the idea that we must not look upon science as a 'body of knowledge,' but rather as a system of hypotheses; that is to say, as a system of guesses or anticipations which in principle cannot be justified, but with which we work as long as they stand up to tests, and of which we are never justified in saying that we know they are 'true' or 'more or less certain' or even 'probable.'
Karl Popper[Great scientists] are men of bold ideas, but highly critical of their own ideas: they try to find whether their ideas are right by trying first to find whether they are not perhaps wrong. They work with bold conjectures and severe attempts at refuting their own conjectures.
Karl PopperThe war of ideas is a Greek invention. It is one of the most important inventions ever made. Indeed, the possibility of fighting with with words and ideas instead of fighting with swords is the very basis of our civilization, and especially of all its legal and parliamentary institutions.
Karl PopperRationalism 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."
Karl Popper