We may grant that so long as no scruple has arisen concerning the morality of flesh-eating, or any other barbarous usage, such practices may be carried on in innocence and good faith, and therefore without personal demoralisation to those who indulge in them. But from the moment when discussion begins, and an unconscious act becomes a conscious or semi-conscious one, the case is wholly different, and it is then impossible to plead that "it does not matter" about one's food. On the contrary, it is a matter of vital import if injustice be deliberately practised. To use flesh-food unwittingly, by savage instinct, as the carnivora do, or, like barbarous mankind, in the ignorance of age-long habit, is one thing; but it is quite another thing for a rational person to make a sophistical defence of such habits when their iniquity has been displayed, and then to claim that he is absolved from guilt by the spirit in which he acted. The spirit that absolves is one of unquestioning faith, not of far-fetched sophistry. The wolf devours the lamb, and is no worse a wolf for it; but if he seek, as in the fable, to give quibbling excuses for his wolfishness, he becomes a byword for hypocrisy.
(Henry S. Salt, The Logic of Vegetarianism: Essays and Dialogues [London: The Ideal Publishing Union, 1899], 77-8 [italics in original])