The peculiarity of the evidence of mathematical truths is that all the argument is on one side.

In this age, the mere example of non-conformity, the mere refusal to bend the knee to custom, is itself a service. Precisely because the tyranny of opinion is such as to make eccentricity a reproach, it is desirable, in order to break through that tyranny, that people should be eccentric. Eccentricity has always abounded when and where strength of character has abounded; and the amount of eccentricity in a society has generally been proportional to the amount of genius, mental vigor, and moral courage which it contained. That so few now dare to be eccentric, marks the chief danger of the time.

Money is a machine for doing quickly and commodiously what would be done, though less quickly and commodiously, without it.

Mankind are greater gainers by suffering each other to live as seems good to themselves, than by compelling each to live as seems good to the rest.

A democratic constitution, not supported by democratic institutions in detail, but confined to the central government, not only is not political freedom, but often creates a spirit precisely the reverse, carrying down to the lowest grade in society the desire and ambition of political domination.

The strongest of all arguments against the interference of the public with purely personal conduct, is that when it does interfere, the odds are that it interferes wrongly, and in the wrong place.

The test of real and vigorous thinking, the thinking which ascertains truths instead of dreaming dreams, is successful application to practice.