Single Idea 3092

[catalogued under 2. Reason / A. Nature of Reason / 9. Limits of Reason]

Full Idea

If a rational man believes he has at least some other false beliefs, it follows that a rational man knows that at least one of his beliefs is false (the one believed false, or this new belief).

Gist of Idea

If you believe that some of your beliefs are false, then at least one of your beliefs IS false

Source

Gilbert Harman (Thought [1973], 7.2)

Book Reference

Harman,Gilbert: 'Thought' [Princeton 1977], p.119