Karl Popper Quotes

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.

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

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.

Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.

'Incontrovertible' is not a scientific word. Nothing is incontrovertible in science.

We don't regard any scientific theory as the absolute truth.

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

Science is a mechanism, a way of trying to improve your knowledge of nature. It's a system for testing your thoughts against the universe, and seeing whether they match.

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

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

Science is at no moment quite right, but it is seldom quite wrong, and has, as a rule, a better chance of being right than the theories of the unscientific. It is, therefore, rational to accept it hypothetically.

The only universal attribute of scientific statements resides in their potential fallibility. If a claim cannot be disproven, it does not belong to the enterprise of science.

There will be well-testable theories, hardly testable theories, and non-testable theories. Those which are non-testable are of no interest to empirical scientists. They may be described as metaphysical.

The real purpose of the scientific method is to make sure nature hasn’t misled you into thinking you know something you actually don’t know.

There never comes a point where a theory can be said to be true. The most that one can claim for any theory is that it has shared the successes of all its rivals and that it has passed at least one test which they have failed.

In science, there are no universal truths, just views of the world that have yet to be shown to be false.

The logic of science was infallible, and if the scientists were sometimes mistaken, this was assumed to be only from their mistaking its rules.

Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it.

The role of science is to be systematic, to be accurate, to be orderly, but it certainly is not to imply that the aggregated, successful hypotheses of the past have the kind of truth that goes into a number system.

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.

As to science, we may well define it for our purpose as "methodical thinking directed toward finding regulative connections between our sensual experiences".

In science , all conclusions are provisional, subject to new evidence and better arguments, the very antithesis of religious faith.

The scientific tradition is distinguished from the pre-scientific tradition by having two layers. Like the latter, it passes on its theories; but it also passes on a critical attitude towards them.

In order that the facts obtained by observation and experiment may be capable of being used in furtherance of our exact and solid knowledge, they must be apprehended and analysed according to some Conceptions which, applied for this purpose, give distinct and definite results, such as can be steadily taken hold of and reasoned from.

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