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.

It is not true that a man can believe or disbelieve what he will. But it is certain that an active desire to find any proposition true will unconsciously tend to that result by dismissing importunate suggestions which run counter to the belief, and welcoming those which favor it. The psychological law, that we only see what interests us, and only assimilate what is adapted to our condition, causes the mind to select its evidence.

Metaphysical ghosts cannot be killed, because they cannot be touched; but they may be dispelled by dispelling the twilight in which shadows and solidities are easily confounded. The Vital Principle is an entity of this ghostly kind; and although the daylight has dissipated it, and positive Biology is no longer vexed with its visitations, it nevertheless reappears in another shape in the shadowy region of mystery which surrounds biological and all other questions.

Speak for yourself and from yourself, or be silent.

Every one who has seriously investigated a novel question, who has really interrogated Nature with a view to a distinct answer, will bear me out in saying that it requires intense and sustained effort of imagination.

In Science the paramount appeal is to the Intellect-its purpose being instruction; in Art, the paramount appeal is to the Emotions-its purpose being pleasure.

The magic of the pen lies in the concentration of your thoughts upon one object.