He who lets the world choose his plan of life for him has need of no other faculty than that of ape-like imitation.

If opponents of all important truths do not exist, it is indispensable to imagine them and supply them with the strongest arguments which the most skillful devil's advocate can conjure up.

The individual is not accountable to society for his actions in so far as these concern the interests of no person but himself.

The most cogent reason for restricting the interference of government is the great evil of adding unnecessarily to its power.

Seeming contentment is real discontent, combined with indolence or self-indulgence, which, while taking no legitimate means of raising itself, delights in bringing others down to its own level.

There is one characteristic of the present direction of public opinion, peculiarly calculated to make it intolerant of any marked demonstration of individuality. The general average of mankind are not only moderate in intellect, but also moderate in inclinations: they have no tastes or wishes strong enough to incline them to do anything unusual, and they consequently do not understand those who have, and class all such with the wild and intemperate whom they are accustomed to look down upon.

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