In the Life of Darwin by his son, there is related an incident of how the great naturalist once studied long as to just what a certain spore was. Finally he said, "It is this, for if it isn't, then what is it?" And all during his life he was never able to forget that he had been guilty of this unscientific attitude, for science is founded on certitude, not assumption.

How many a man has thrown up his hands at a time when a little more effort, a little more patience would have achieved success.

A woman will doubt everything you say except it be compliments to herself.

Dignity is a mask we wear to hide our ignorance.

When certain unmarried men, who had lost their capacity to sin, sat indoors, breathing bad air, and passed resolutions about what was right and what wrong, making rules for the guidance of the people, instead of trusting to the natural, happy instincts of the individual, they ushered in the Dark Ages. These are the gentlemen who blocked human evolution absolutely for a thousand years.

The wise way to benefit humanity is to attend to your own affairs, and thus give other people an opportunity to look after theirs.

When trouble comes, wise men take to their work; weak men take to the woods.