Karl Popper Quotes

Science is the acceptance of what works and the rejection of what does not. That needs more courage than we might think.

A system such as classical mechanics may be 'scientific' to any degree you like; but those who uphold it dogmatically - believing, perhaps, that it is their business to defend such a successful system against criticism as long as it is not conclusively disproved - are adopting the very reverse of that critical attitude which in my view is the proper one for the scientist.

The work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.

We must conduct research and then accept the results. If they don't stand up to experimentation, Buddha's own words must be rejected.

Imagination should give wings to our thoughts but we always need decisive experimental proof, and when the moment comes to draw conclusions and to interpret the gathered observations, imagination must be checked and documented by the factual results of the experiment.

Science is not the affirmation of a set of beliefs but a process of inquiry aimed at building a testable body of knowledge constantly open to rejection or confirmation. In science, knowledge is fluid and certainty fleeting. That is at the heart of its limitations. It is also its greatest strength.

It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is if it disagrees with experiment it is wrong. That is all there is to it.

The tendencies are considerably weaker in the natural sciences, which, for the past several centuries, have survived and flourished through such constant challenge, and therefore, at best, seek to encourage it. Serving the status quo in political and socioeconomic realms is a different matter.

It is a mistake to believe that science consists in nothing but conclusively proved propositions, and it is unjust to demand that it should. It is a demand made by those who feel a craving for authority in some form to replace the religious catechism by something else, even a scientific one.

The method of science is tried and true. It is not perfect, it's just the best we have. And to abandon it, with its skeptical protocols, is the pathway to a dark age.

A single test which proves some piece of theory wrong is more valuable than a hundred tests showing that idea might be true.

Reason, observation, and experience; the holy trinity of science.

One must credit an hypothesis with all that has had to be discovered in order to demolish it.

True science is never speculative; it employs hypotheses as suggesting points for inquiry, but it never adopts the hypotheses as though they were demonstrated propositions.

The man of science has learned to believe in justification, not by faith, but by verification.

A scientist... must accept the results of experiment, and nothing but the results of experiment.

Educated guesswork' is what science is. You form hypotheses, test them against the evidence, and if they fit the evidence, you can assume you've got close to the truth.

The public has a distorted view of science because children are taught in school that science is a collection of firmly established truths. In fact, science is not a collection of truths. It is a continuing exploration of mysteries.

There are many hypotheses in science which are wrong. That’s perfectly all right: it’s the aperture to finding out what’s right. Science is a self-correcting process.

Galileo probably would have escaped persecution if his discoveries could have been disproved.

In degenerating programmes, however, theories are fabricated only in order to accommodate known facts

There is no more common error than to assume that, because prolonged and accurate mathematical calculations have been made, the application of the result to some fact of nature is absolutely certain.

Science doesn't purvey absolute truth. Science is a mechanism... for testing your thoughts against the universe.

One of the reasons for its success is that science has a built-in, error-correcting machinery at its very heart. Some may consider this an overbroad characterization, but to me every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self-indulgent and uncritical, when we confuse hopes and facts, we slide into pseudoscience and superstition.

Science is nothing but trained and organized common sense differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.