Full Idea
The most fundamental notion in classical logic is that of truth.
Gist of Idea
Truth is the basic notion in classical logic
Source
David Bostock (Intermediate Logic [1997], 1.1)
Book Reference
Bostock,David: 'Intermediate Logic' [OUP 1997], p.3
A Reaction
The opening sentence of his book. Hence the first half of the book is about semantics, and only the second half deals with proof. Compare Idea 10282. The thought seems to be that you could leave out truth, but that makes logic pointless.
Related Idea
Idea 10282 Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]