"In a word, whoever will consult common sense upon religious opinions, and will carry into this examination the attention given to objects of ordinary interest, will easily perceive that these opinions have no solid foundation; that all religion is but a castle in the air; that Theology is but ignorance of natural causes reduced to a system; that it is but a long tissue of chimeras and contradictions; that it presents to all the different nations of the earth only romances devoid of probability, of which the hero himself is made up of qualities impossible to reconcile, his name having the power to excite in all hearts respect and fear, is found to be but a vague word, which men continually utter, being able to attach to it only such ideas or qualities as are belied by the facts, or which evidently contradict each other."

“How I suffered when I had to preach to you those pious lies that I detest in my heart. What remorse your credulity caused me! A thousand times I was on the point of breaking out publicly and opening your eyes, but a fear stronger than myself held me back, and forced me to keep silence until my death.”

“When we wish to examine in a cool, calm way the opinions of men, we are very much surprised to find that in those which we consider the most essential, nothing is more rare than to find them using common sense; that is to say, the portion of judgment sufficient to know the most simple truths, to reject the most striking absurdities, and to be shocked by palpable contradictions.”

“It is an act of cruelty, of barbarism, to kill, to strike unconscious, and to cut the throat of animals, who do no harm to anyone, the way we do; because they are sensitive to injury and pain just as we are, regardless of what is said vainly, falsely, and ridiculously by our new Cartesians, who regard them as purely machines without soul and without feelings … This is a ridiculous opinion, a pernicious principle, and a detestable doctrine, because it clearly tends to stifle in the hearts of men all feelings of kindness, of gentleness, and of humanity that they might have toward these poor animals. … Blessed are the nations that treat them kindly and favorably, who are compassionate toward their miseries and their pains; but cursed are the nations that treat them cruelly, who tyrannize over them, who enjoy shedding their blood, and who are avid to eat their flesh.”