Until every soul is freely permitted to investigate every book, and creed, and dogma for itself, the world cannot be free. Mankind will be enslaved until there is mental grandeur enough to allow each man to have his thought and say. This earth will be a paradise when men can, upon all these questions differ, and yet grasp each other’s hands as friends. It is amazing to me that a difference of opinion upon subjects that we know nothing with certainty about, should make us hate, persecute, and despise each other.
—Robert Green Ingersoll, Some Mistakes of Moses