Genius... means little more than the faculty of perceiving in an unhabitual way.

One hears of the mechanical equivalent of heat. What we now need to discover in the social realm is the moral equivalent of war: something heroic that will speak to men as universally as war does, and yet will be as compatible with their spiritual selves as war has proved itself to be incompatible.

The first effect of the mind growing cultivated is that processes once multiple get to be performed in a single act. Lazarus has called this the progressive "condensation" of thought. ... Steps really sink from sight. An advanced thinker sees the relations of his topics is such masses and so instantaneously that when he comes to explain to younger minds it is often hard ... Bowditch, who translated and annotated Laplace's Méchanique Céleste, said that whenever his author prefaced a proposition by the words "it is evident," he knew that many hours of hard study lay before him.

We forget that every good that is worth possessing must be paid for in strokes of daily effort.

Volition . . . takes place only when there are a number of conflicting systems of ideas, and depends on our having a complex field of consciousness.

The world is all the richer for having a devil in it, so long as we keep our foot upon his neck.

For I had often said that the best argument I knew for an immortal life was the existence of a man who deserved one as well as Child did.