It is a thing of no great difficulty to raise objections against another man's oration, it is a very easy matter; but to produce a better in it's place is a work extremely troublesome.

When Demosthenes was asked what were the three most important aspects of oratory, he answered, 'Action, Action, Action.'

Silence is an answer to a wise man.

Choose what is best, and habit will make it pleasant and easy.

Those are greedy of praise prove that they are poor in merit.

This excerpt is presented as reproduced by Copernicus in the preface to De Revolutionibus: "Some think that the earth remains at rest. But Philolaus the Pythagorean believes that, like the sun and moon, it revolves around the fire in an oblique circle. Heraclides of Pontus and Ecphantus the Pythagorean make the earth move, not in a progressive motion, but like a wheel in rotation from west to east around its own center."

He is a fool who leaves things close at hand to follow what is out of reach.