Man is a fighting animal; his thoughts are his banners, and it is a failure of nerve in him if they are only thoughts.

The creative phase of an idea coincides with the period during which it insists, cantankerously, on its boundaries, on what makes it different; but an idea becomes false and impotent when it seeks reconciliation, at cut-rate prices, with other ideas.

Every action is an idea before it is an action, and perhaps a feeling before it is an idea, and every idea rests upon other ideas that have preceded it in time.

If an idea cannot move on its own, pushing it doesn't help; best to let it lie there.

The slowness of one section of the world about adopting the valuable ideas of another section of it is a curious thing and unaccountable.

An idea does not pass from one language to another without change.

No man can establish title to an idea-at the most he can only claim possession. The stream of thought that irrigates the mind of each of us is a confluent of the intellectual river that drains the whole of the living universe.

Human life is driven forward by its dim apprehension of notions too general for its existing language.

Every man is wise when attacked by a mad dog; fewer when pursued by a mad woman; only the wisest survive when attacked by a mad notion.

All the really good ideas I ever had came to me while I was milking a cow.