We live in the hope and faith that, by the advance of molecular physics, we shall by-and-by be able to see our way as clearly from the constituents of water to the properties of water, as we are now able to deduce the operations of a watch from the form of its parts and the manner in which they are put together.

The occurrence of successive forms of life upon our globe is an historical fact, which cannot be disputed; and the relation of these successive forms, as stages of evolution of the same type, is established in various cases.

The great end of life is not knowledge but action.

What are the moral convictions most fondly held by barbarous and semi-barbarous people? They are the convictions that authority is the soundest basis of belief; that merit attaches to readiness to believe; that the doubting disposition is a bad one, and skepticism is a sin.

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

Genius, as an explosive power, beats gunpowder hollow.

The population question is the real riddle of the sphinx, to which no political Oedipus has as yet found the answer. In view of the ravages of the terrible monster over-multiplication, all other riddle sink into insignificance.