It is just because civilization is ever evolving, changing, and becoming more complicated, that experts find it so difficult to define it in explicit terms.

I prize the conditions under which I have lived because they have permitted me to choose my opportunities, to inquire into such matters as interested me, and to publish what I believed to be true, uncontrolled by any central authority.

Reason has not tamed desire: it is as strong as ever.

In a tribal organization, even in time of peace, service to tribe or state predominates over all self seeking; in war, service for the tribe or state becomes supreme, and personal liberty is suspended.

The course of human history is determined, not by what happens in the skies, but what takes place in our hearts.

Tolerance is held to be a condition of mind which is encouraged by, and is necessary for, civilization.

No tempting form of error is without some latent charm derived from truth.