Karl Popper Quotes

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.

Every genuine test of a theory is an attempt to falsify it, or to refute it.

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.

It is a truism to say that a good experiment is precisely that which spares us the exertion of thinking: the better it is, the less we have to worry about its interpretation, about what it really means.

The philosophy of science is inherent in the process. This is to say, you think critically, you draw a conclusion based on evidence, but we all pursue discovery based on our observations. That's where science starts.

I don't think the scientific method and the science fictional method are really analogous. The thing about them is that neither is really practiced very much, at least not consciously. But the fact that they are methodical does relate them.

What intrigues basic scientists like me is that anytime we do a series of experiments, there are going to be three or four new questions that come up when you think you've answered one.

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

If you're a physicist, for heaven's sake, and here is the experiment, and you have a theory, and the theory doesn't agree with the experiment, then you have to cut out the theory. You were wrong with the theory.

Hypotheses are what we lack the least.

I am not here concerned with intent, but with scientific standards, especially the ability to tell the difference between a fact, an opinion, a hypothesis, and a hole in the ground.

The criterion of the scientific status of a theory is its falsifiability, or refutability, or testability.

Okay, are you really 'experimenting'? How do you know if you're really experimenting? You're working on it methodically and you're publishing the results! It's not an experiment if you don't publish the results in some verifiable and falsifiable form, okay?

Scientific method: There's a madness in the method.

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

[One's] inability to invalidate your hypothesis is not at all the same thing as proving it true.

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.

Why should there be the method of science? There is not just one way to build a house, or even to grow tomatoes. We should not expect something as motley as the growth of knowledge to be strapped to one methodology.

One of the ways of stopping science would be only to do experiments in the region where you know the law. But experimenters search most diligently, and with the greatest effort, in exactly those places where it seems most likely that we can prove our theories wrong. In other words, we are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.

The method of scientific investigation is nothing but the expression of the necessary mode of working of the human mind.

It is impossible to devise an experiment without a preconceived idea; devising an experiment, we said, is putting a question; we never conceive a question without an idea which invites an answer. I consider it, therefore, an absolute principle that experiments must always be devised in view of a preconceived idea, no matter if the idea be not very clear nor very well defined.

Natural science is founded on minute critical views of the general order of events taking place upon our globe, corrected, enlarged, or exalted by experiments, in which the agents concerned are placed under new circumstances, and their diversified properties separately examined. The body of natural science, then, consists of facts; is analogy,-the relation of resemblance of facts by which its different parts are connected, arranged, and employed, either for popular use, or for new speculative improvements.

I think science has a better story to tell than anyone else has been able to tell and that's because it's based on the rigorous winnowing that science and scientists are always doing in order to find out what's really happening. I think it's really good to encourage generally our ability to tell stories and that's a great skill that we come by naturally, so I'm excited about that.

In these researches I followed the principles of the experimental method that we have established, i.e., that, in presence of a well-noted, new fact which contradicts a theory, instead of keeping the theory and abandoning the fact, I should keep and study the fact, and I hastened to give up the theory.

The purpose of scientific method is to select a single truth from among many hypothetical truths. That, more than anything else, is what science is all about. But historically science has done exactly the opposite. Through multiplication upon multiplication of facts, information, theories and hypotheses, it is science itself that is leading mankind from single absolute truths to multiple indeterminate, relative ones.