Full Idea
Although reason exists forever, men are foolish.
Gist of Idea
Reason is eternal, but men are foolish
Source
Heraclitus (fragments/reports [c.500 BCE]), quoted by Aristotle - The Art of Rhetoric 1407b
Book Reference
Aristotle: 'The Art of Rhetoric', ed/tr. Lawson-Tancred,H.C. [Penguin 1991], p.226
A Reaction
The despair of all philosophers (e.g. Plato) who think reason is the easiest thing in the world, and stares everyone in the face, and yet people seem to spurn this supreme gift from the gods. They needed the optimism of the career teacher.