Russell: 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.
Are these the two things we need to be free of intellectually? Are there other things that we should think about being free from in order to be rational? Intellectual peer pressure, maybe?