The Logic of Scientific Discovery

By Karl R. Popper | Go to book overview
Save to active project


THEORIES are not verifiable, but they can be 'corroborated'.

The attempt has often been made to describe theories as being neither true nor false, but instead more or less probable. Inductive logic, more especially, has been developed as a logic which may ascribe not only the two values 'true' and 'false' to statements, but also degrees of probability; a type of logic which will here be called 'probability logic'. According to those who believe in probability logic, induction should determine the degree of probability of a statement. And a principle of induction should either make it sure that the induced statement is 'probably valid' or else it should make it probable, in its turn--for the principle of induction might itself be only 'probably valid'. Yet in my view, the whole problem of the probability of hypotheses is misconceived. Instead of discussing the 'probability' of a hypothesis we should try to assess what tests, what trials, it has withstood; that is, we should try to assess how far it has been able to prove its fitness to survive by standing up to tests. In brief, we should try to assess how far it has been 'corroborated'.*1

I introduced the terms 'corroboration' ('Bewæhrung') and especially 'degree of corroboration' ('Grad der Bewæhrung', 'Bewæhrungsgrad') in my book because I wanted a neutral term to describe the degree to which a hypothesis has stood up to severe tests, and thus 'proved its mettle'. By 'neutral' I mean a term not prejudging the issue whether, by standing up to tests, the hypothesis becomes 'more probable', in the sense of the probability calculus. In other words, I introduced the term 'degree of corroboration' mainly in order to be able to discuss the problem whether or not degree of corroboration' could be indentified with 'probability' (either in a frequency sense or in the sense of Keynes, for example).

Carnap translated my term 'degree of corroboration' ('Grad der Bewæhrung'), which I had first introduced into the discussions of the Vienna Circle, as 'degree of confirmation'. (See his "'Testability and Meaning'", in Philosophy of Science 3, 1936; especially p. 427); and so the term 'degree of confirmation' soon became widely accepted. I did not like this term, because of some of its associations ('make firm'; 'establish firmly';


Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Cite this page

Cited page

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited page

Bookmark this page
The Logic of Scientific Discovery


Text size Smaller Larger
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen
/ 480

matching results for page

Cited passage

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?