If a man cannot see a church, it is preposterous to take his opinion about its altar-piece or painted window.

The man of science has learned to believe in justification, not by faith, but by verification.

There are savages without God in any proper sense of the word, but none without ghosts.

Not only does every animal live at the expense of some other animal or plant, but the very plants are at war.... The individuals of a species are like the crew of a foundered ship, and none but good swimmers have a chance of reaching the land.

No delusion is greater than the notion that method and industry can make up for lack of mother-wit, either in science or in practical life.

The only people, scientific or other, who never make mistakes are those who do nothing.

The only medicine for suffering, crime, and all other woes of mankind, is wisdom. Teach a man to read and write, and you have put into his hands the great keys of the wisdom box. But it is quite another thing to open the box.