more from Gottlob Frege

Single Idea 16865

[catalogued under 5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic]

Full Idea

Usually a truth is only called a 'theorem' when it has not merely been obtained by inference, but is used in turn as a premise for a number of inferences in the science. .Proofs use non-theorems, which only occur in that proof.

Gist of Idea

'Theorems' are both proved, and used in proofs

Source

Gottlob Frege (Logic in Mathematics [1914], p.204)

Book Reference

Frege,Gottlob: 'Posthumous Writings', ed/tr. Hermes/Long/White etc [Blackwell 1979], p.204