A cat can be trusted to purr when she is pleased, which is more than can be said for human beings.

Boredom is a certain sign that we are allowing our faculties to rust in idleness.

No healthy civilization can ever be reared on a foundation of devitalized work.

The whole of nature, as has been said, is a conjugation of the verb to eat, in the active and in the passive.

Over-population is a phenomenon connected with the survival of the unfit, and it is a mechanism which has created conditions favourable to the survival of the unfit and the elimination of the fit.

There is no law of progress. Our future is in our own hands, to make or to mar. It will be an uphill fight to the end, and would we have it otherwise? Let no one suppose that evolution will ever exempt us from struggles. 'You forget,' said the Devil, with a chuckle, 'that I have been evolving too.

The game of life is worth playing, but the struggle is the prize.