To love the truth, thus perceived, is mental virtue—intellectual purity. This is true manhood. This is freedom.
To throw away your reason at the command of churches, popes, parties, kings or gods, is to be a serf, a slave.
It is not simply the right, but it is the duty of every man to think—to investigate for himself—and every man who tries to prevent this by force or fear, is doing all he can to degrade and enslave his fellow-men.
Every Man Should be Mentally Honest.
He should preserve as his most precious jewel the perfect veracity of his soul.
He should examine all questions presented to his mind, without prejudice,—unbiased by hatred or love—by desire or fear. His object and his only object should be to find the truth. He knows, if he listens to reason, that truth is not dangerous and that error is. He should weigh the evidence, the arguments, in honest scales—scales that passion or interest cannot change. He should care nothing for authority—nothing for names, customs or creeds—nothing for anything that his reason does not say is true.
Of his world he should be the sovereign, and his soul should wear the purple. From his dominions should be banished the hosts of force and fear.
He Should be Intellectually Hospitable.
Prejudice, egotism, hatred, contempt, disdain, are the enemies of truth and progress.
The real searcher after truth will not receive the old because it is old, or reject the new because it is new. He will not believe men because they are dead, or contradict them because they are alive. With him an utterance is worth the truth, the reason it contains, without the slightest regard to the author. He may have been a king or serf—a philosopher or servant,—but the utterance neither gains nor loses in truth or reason. Its value is absolutely independent of the fame or station of the man who gave it to the world.