For a young person, it is almost a sin, or at least a danger, to be too preoccupied with himself; but for the ageing person, it is a duty and a necessity to devote serious attention to himself.

He will win who knows when to fight and when not to fight.

Capital is dead labor, which, vampire-like, lives only by sucking living labor, and lives the more, the more labor it sucks.

Men give away nothing so liberally as their advice.

There is no such thing as a pure introvert or extrovert. Such a person would be in the lunatic asylum.