Though under-instruction is a bad thing, it is not impossible that over-instruction may be worse.

Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third.

The secret of genius is to carry the spirit of childhood into maturity.

That mysterious independent variable of political calculation, Public Opinion.

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.

I really see no harm which can come of giving our children a little knowledge of physiology. ... The instruction must be real, based upon observation, eked out by good explanatory diagrams and models, and conveyed by a teacher whose own knowledge has been acquired by a study of the facts; and not the mere catechismal parrot-work which too often usurps the place of elementary teaching.

There is no sadder sight in the world than to see a beautiful theory killed by a brutal fact.