Ritson begins his Essay with a brief review of the opinions of some of the old Greek and Italian philosophers upon the origin and constitution of the world, and with a sketch of the position of man in Nature relatively to other animals. Amongst others he cites Rousseau’s Essay _Upon Inequality Amongst Men_. He then demonstrates the unnaturalness of flesh-eating by considerations derived from Physiology and Anatomy, and from the writings of various authorities; the fallacy of the prejudice that flesh-meats are necessary or conducive to strength of body, a fallacy manifest as well from the examples of whole nations living entirely, or almost entirely, upon non-flesh food, as from those of numerous individuals whose cases are detailed at length. He quotes Arbuthnot, Sir Hans Sloane, Cheyne, Adam Smith, Volney, Paley, and others. Next he insists upon the ferocity or coarseness of mind directly or indirectly engendered by the diet of blood:-- “That the use of animal food disposes man to cruel and ferocious actions is a fact to which the experience of ages gives ample testimony. The Scythians, from drinking the blood of their cattle, proceeded to drink that of their enemies. The fierce and cruel disposition of the wild Arabs is supposed chiefly, if not solely, to arise from their feeding upon the flesh of camels: and as the gentle disposition of the natives of Hindustan is probably owing, in great degree, to temperance and abstinence from animal food, so the common use of this diet, with other nations, has, in the opinion of M. Pagès, intensified the natural tone of their passions; and he can account, he says, upon no other principle, for the strong, harsh features of the Mussulmen and the Christians compared with the mild traits and placid aspect of the Gentoos. ‘Vulgar and uninformed men,’ it is observed by Smellie, ‘when pampered with a variety of animal food, are much more choleric, fierce, and cruel in their tempers, than those who live chiefly upon vegetables.’ This affection is equally perceptible in other animals--‘An officer, in the Russian service, had a bear whom he fed with bread and oats, but never gave him flesh. A young hog, however, happening to stroll near his cell, the bear got hold of him and pulled him in; and, after he had once drawn blood and tasted flesh, he became unmanageable, attacking every person who came near him, so that the owner was obliged to kill him.’--[_Memoirs of P. H. Bruce._] It was not, says Porphyry, from those who lived on vegetables that robbers, or murderers, or tyrants have proceeded, but from flesh-eaters.[208] Prey being almost the sole object of quarrel amongst carnivorous animals, while the frugivorous live together in constant peace and harmony, it is evident that if men were of this latter kind, they would find it much more easy to subsist happily.”