What a pity and what a poverty of spirit, to assert that beasts are machines deprived of knowledge and sentiment, which affect all their operations in the same manner, which learn nothing, never improve, &c. [...] Some barbarians seize this dog, who so prodigiously excels man in friendship, they nail him to a table, and dissect him living, to show the mezarian veins. You discover in him all the same organs of sentiment which are in yourself. Answer me, machinist, has nature arranged all the springs of sentiment in this animal that he should not feel? Has he nerves to be incapable of suffering? Do not suppose this impertinent contradiction in nature. [...] The animal has received those of sentiment, memory, and a certain number of ideas. Who has bestowed these gifts, who has given these faculties? He who has made the herb of the field to grow, and who makes the earth gravitate towards the sun.

Ours is assuredly the most ridiculous, the most absurd and the most bloody religion which has ever infected this world. Your Majesty will do the human race an eternal service by extirpating this infamous superstition, I do not say among the rabble, who are not worthy of being enlightened and who are apt for every yoke; I say among honest people, among men who think, among those who wish to think. ... My one regret in dying is that I cannot aid you in this noble enterprise, the finest and most respectable which the human mind can point out.