Let us have "sweet girl graduates" by all means. They will be none the less sweet for a little wisdom; and the "golden hair" will not curl less gracefully outside the head by reason of there being brains within.

To say that an idea is necessary is simply to affirm that we cannot conceive the contrary; and the fact that we cannot conceive the contrary of any belief may be a presumption, but is certainly no proof, of its truth.

If individuality has no play, society does not advance; if individuality breaks out of all bounds, society perishes.

The struggle for existence holds as much in the intellectual as in the physical world. A theory is a species of thinking, and its right to exist is coextensive with its power of resisting extinction by its rivals.

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 doctrine that all men are, in any sense, or have been, at any time, free and equal, is an utterly baseless fiction.

Every great advance in natural knowledge has involved the absolute rejection of authority.