Our morality seems to be only a check on the ultimate domination of force, just as our politeness is a check on the impulse of every pig to put his feet in the trough.

Life, not the parson, teaches conduct.

Any tax is a discouragement and therefore a regulation so far as it goes.

As for the excellent little wretches who grow up in what they are taught, with never a scruple or a query, ... they signify nothing in the intellectual life of the race.

There is nothing earthly that lasts so well, as money. A man's learning dies with him, as does his virtues fade out of remembrance, but the dividends on the stocks he bequeaths to his children live and keep his memory green.

To be civilized is to be potentially master of all possible ideas, and that means that one has got beyond being shocked, although one preserves one's own moral aesthetic preferences.

Longevity is having a chronic disease - and taking care of it.