Single Idea 17638

[catalogued under 2. Reason / A. Nature of Reason / 6. Coherence]

Full Idea

Two obvious propositions of which one can be deduced from the other both become more certain than either in isolation; thus in a complicated deductive system, many parts of which are obvious, the total probability may become all but absolute certainty.

Gist of Idea

If one proposition is deduced from another, they are more certain together than alone

Source

Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.279)

Book Reference

Russell,Bertrand: 'Essays in Analysis', ed/tr. Lackey,Douglas [George Braziller 1973], p.279


A Reaction

Thagard picked this remark out, in support of his work on coherence.