Intelligence is the only moral guide.

As a man develops, he places a greater value upon his own rights. Liberty becomes a grander and diviner thing. As he values his own rights he begins to value the rights of others. And when all men give to all others all the rights they claim for themselves, this world will be civilized.

It is impossible for me to conceive of a character more utterly detestable than that of the Hebrew god.

To avoid pain we must know the conditions of health. For the accomplishment of this end we must rely upon investigation instead of faith, upon labor in place of prayer. Most misery is produced by ignorance. Passions sow the seeds of pain.

Orthodoxy cannot afford to put out the fires of hell.

I believe that there is something far nobler than loyalty to any particular man. Loyalty to the truth as we perceive it - loyalty to our duty as we know it - loyalty to the ideals of our brain and heart - is, to my mind, far greater and far nobler than loyalty to the life of any particular man or God. . . .

The church hates a thinker precisely for the same reason a robber dislikes a sheriff, or a thief despises the prosecuting witness.