There is no sea more dangerous than the ocean of practical politics none in which there is more need of good pilotage and of a single, unfaltering purpose when the waves rise high.

I am not afraid of the priests in the long-run. Scientific method is the white ant which will slowly but surely destroy their fortifications. And the importance of scientific method in modern practical life--always growing and increasing--is the guarantee for the gradual emancipation of the ignorant upper and lower classes, the former of whom especially are the strength of the priests.

Oh devil! truth is better than much profit. I have searched over the grounds of my belief, and if wife and child and name and fame were all to be lost to me one after the other as the penalty, still I will not lie.

[Scientists] have learned to respect nothing but evidence, and to believe that their highest duty lies in submitting to it however it may jar against their inclinations.

My experience of the world is that things left to themselves don't get right.

Mathematics may be compared to a mill of exquisite workmanship, which grinds your stuff to any degree of fineness.

Whatever part of the animal fabric whatever series of muscles, whatever viscera might be selected for comparison the result would be the same the lower Apes and the Gorilla would differ more than the Gorilla and the Man.