“If an opinion contrary to your own makes you angry, that is a sign that you are subsciously aware of having no good reason for thinking as you do. [...] The most savage controversies are those about matters as to which there is no good evidence either way. Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion. So whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find, on examination, that your belief is going beyond what the evidence warrants.”

“Happiness is not fame or riches or heroic virtues, but a state that will inspire posterity to think in reflecting upon our life, that it was the life they would wish to live.”

“The holy word of God is on everyone's lips...but...we see almost everyone presenting their own versions of God's word, with the sole purpose of using religion as a pretext for making others think as they do.”

“People thinking for themselves have more energy in their voice, than any government, which it is possible for human wisdom to invent; and every government not aware of this sacred truth will, at some period, be suddenly overturned.”

“Time is made up of various ages; and each thinks its own a novelty.”

“The propagandist's purpose is to make one set of people forget that certain other sets of people are human.”

“If an opinion contrary to your own makes you angry, that is a sign that you are subconsciously aware of having no good reason for thinking as you do.”