The expression ‘free thought’ is often used as if it meant merely opposition to the prevailing orthodoxy. But this is only a symptom of free thought, frequent, but invariable. ‘Free thought’ means thinking freely — as freely, at least, as is possible for a human being. The person who is free in any respect is free from something; what is the free thinker free from? To be worthy of the name, he must be free of two things: the force of tradition, and the tyrant of his own passions. No one is completely free from either, but in the measure of a man’s emancipation he deserves to be called a free thinker.