„Man lives very well upon flesh, you say, but, if he thinks this food to be natural to him, why does he not use it as it is, as furnished to him by Nature? But, in fact, he shrinks in horror from seizing and rending living or even raw flesh with his teeth, and lights a fire to change its natural and proper condition. … What is clearer than that man is not furnished for hunting, much less for eating, other animals? In one word, we seem to be admirably admonished by Cicero that man was destined for other things than for seizing and cutting the throats of other animals. If you answer that ‘that may be said to be an industry ordered by Nature, by which such weapons are invented,’ then, behold! it is by the very same artificial instrument that men make weapons for mutual slaughter. Do they this at the instigation of Nature? Can a use so noxious be called natural? Faculty is given by Nature, but it is our own fault that we make a perverse use of it.“
— Pierre Gassendi
Letter to Van Helmont, quoted in The Ethics of Diet: A Catena of Authorities Deprecatory of the Practice of Flesh-eating https://archive.org/stream/ethicsofdietcate00will/ethicsofdietcate00will#page/n3/mode/2up by Howard Williams (London: F. Pitman, 1883), pp. 103-104.