Heart and Brain are the two lords of life. In the metaphors of ordinary speech and in the stricter language of science, we use these terms to indicate two central powers, from which all motives radiate, to which all influences converge.

There are many justifications of silence; there can be none of insincerity.

No man ever made a great discovery without the exercise of the imagination.

Philosophy and Art both render the invisible visible by imagination.

Vehemence without feeling is but rant.

A man may be buoyed up by the efflation of his wild desires to brave any imaginable peril; but he cannot calmly see one he loves braving the same peril; simply because he cannot feel within turn that which prompts another. He sees the danger, and feels not the power that is to overcome it.

Not only the individual experience slowly acquired, but the accumulated experience of the race, organized in language, condensed in instruments and axioms, and in what may be called the inherited intuitions--these form the multiple unity which is expressed in the abstract term "experience.