Try to learn something about everything and everything about something.

The strongest man in the world is the man who stands alone.

The deepest sin against the human mind is to believe things without evidence.

Science is nothing but trained and organized common sense, differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.

Make up your mind to act decidedly and take the consequences. No good is ever done in this world by hesitation.

Irrationally held truths may be more harmful than reasoned errors.

Every great advance in natural knowledge has involved the absolute rejection of authority.

Agnosticism simply means that a man shall not say he knows or believes that for which he has no grounds for professing to believe.