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.

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.

Ideas are forces; our acceptance of one determines our reception of others.

When a man fails to see the truth of certain generally accepted views, there is no law compelling him to provoke animosity by announcing his dissent.

Originality is independence, not rebellion; it is sincerity, not antagonism.

Many a genius has been slow of growth. Oaks that flourish for a thousand years do not spring up into beauty like a reed.

Science is the systematic classification of experience.