However unwillingly a person who has a strong opinion may admit the possibility that his opinion may be false, he ought to be moved by the consideration that, however true it may be, if it is not fully, frequently, and fearlessly discussed, it will be held as a dead dogma, not a living truth.

Induction is a process of inference; it proceeds from the known to the unknown.

The moment one asks himself whether he is happy, he ceases to be so.

Complete liberty of contradicting and disproving our opinion, is the very condition which justifies us in assuming its truth for purposes of action.

War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war is much worse.

A government with all this mass of favours to give or to withhold, however free in name, wields a power of bribery scarcely surpassed by an avowed autocracy, rendering it master of the elections in almost any circumstances but those of rare and extraordinary public excitement.

The liberty of the individual must be thus far limited; he must not make himself a nuisance to other people.