Love can only flourish as long as it is free and spontaneous; it tends to be killed by the thought that it is a duty. To say that it is your duty to love so-and-so is the surest way to cause you to hate him or her.

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.

The satisfaction to be derived from success in a great constructive enterprise is one of the most massive that life has to offer.

All human activity is prompted by desire.

What is wanted is not the will to believe, but the will to find out, which is the exact opposite.

Find more pleasure in intelligent dissent than in passive agreement, for, if you value intelligence as you should, the former implies a deeper agreement than the latter.

The infliction of cruelty with a good conscience is a delight to moralists - that is why they invented hell.