Vanity is a motive of immense potency.

When a man tells you that he knows the exact truth about anything you are safe in inferring that he is an inexact man.

Calculus required continuity, and continuity was supposed to require the infinitely little; but nobody could discover what the infinitely little might be.

To conquer fear is the beginning of wisdom.

To be able to fill leisure intelligently is the last product of civilization, and at present very few people have reached this level.

Thee might observe incidentally that if the state paid for child-bearing it might and ought to require a medical certificate that the parents were such as to give a reasonable result of a healthy child -- this would afford a very good inducement to some sort of care for the race, and gradually as public opinion became educated by the law, it might react on the law and make that more stringent, until one got to some state of things in which there would be a little genuine care for the race, instead of the present haphazard higgledy-piggledy ways.

To save the world requires faith and courage: faith in reason, and courage to proclaim what reason shows to be true.