Exert your talents, and distinguish yourself, and don't think of retiring from the world, until the world will be sorry that you retire.

Hoc age ['do this'] is the great rule, whether you are serious or merry; whether ... learning science or duty from a folio, or floating on the Thames. Intentions must be gathered from acts.

He who has so little knowledge of human nature as to seek happiness by changing anything but his own disposition will waste his life in fruitless efforts.

Reason and truth will prevail at last

I never desire to converse with a man who has written more than he has read.

Curiosity is one of the permanent and certain characteristics of a vigorous intellect. Every advance into knowledge opens new prospects, and produces new incitements to farther progress.

A man will turn over half a library to make one book.