Quotation
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“In so far as a scientific statement speaks about reality, it must be falsifiable; and in so far as it is not falsifiable, it does not speak about reality.”
Karl Popper · Philosophy of science · Modern · 1934; English edition 1959
What does it mean?
In so far as a scientific statement speaks about reality, it must be falsifiable; and in so far as it is not falsifiable, it does not speak about reality. A claim about the world has to be able to clash with some possible observation. A rival reading says this canonises a fantasy of crisp tests, and that living sciences protect their cores and shift the blame to auxiliary assumptions. He knows the practice is messier than the slogan. He still thinks a theory that no possible observation could threaten is not telling you about the world.
Did Karl Popper really say this?
The library’s label is Well attested. Popper's formulation of the falsifiability criterion, in the English edition of Logik der Forschung. The two-part sentence is the one to keep intact.
Where it comes from
The Logic of Scientific Discovery
Approximate date: 1934; English edition 1959.
How to use it
Ask of a theory you favour, in a newsroom in London or a lab in Cambridge, what would show it is wrong. If the answer is nothing, you can still like it. You should stop calling it a scientific claim about the world. If the answer is a test you would never accept, you have not really answered.
A mindset reading
We corroborate, on his view. We do not verify. A theory that survives a hard test is not thereby shown to be true. Using 'not yet falsified' as a compliment you hand out to your own side is not the criterion.
Understand the philosophy
The Logic of Scientific Discovery argues against induction as the logic of science, and against theories, Marx and Freud as he read them, that he thought could explain any outcome. Whether he is fair to those traditions is part of the later argument, not something this sentence settles.
- knowledge
- mind
FAQ
What does it mean?
In so far as a scientific statement speaks about reality, it must be falsifiable; and in so far as it is not falsifiable, it does not speak about reality. A claim about the world has to be able to clash with some possible observation. A rival reading says this canonises a fantasy of crisp tests, and that living sciences protect their cores and shift the blame to auxiliary assumptions. He knows the practice is messier than the slogan. He still thinks a theory that no possible observation could threaten is not telling you about the world.
Did Karl Popper really say this?
Well attested. Popper's formulation of the falsifiability criterion, in the English edition of Logik der Forschung. The two-part sentence is the one to keep intact.
Which work is it in?
The Logic of Scientific Discovery Approximate date: 1934; English edition 1959.