Dr. Gordon Latto notes carnivorous and omnivorous animals can only move their jaws up and down, and that omnivores "have a blunt tooth, a sharp tooth, a blunt tooth, a sharp tooth--showing that they were destined to deal both with flesh foods from the animal kingdom and foods from the vegetable kingdom...

"Carnivorous mammals and omnivorous mammals cannot perspire except at the extremity of the limbs and the tip of the nose; man perspires all over the body. Finally, our instincts; the carnivorous mammal (which first of all has claws and canine teeth) is capable of tearing flesh asunder, whereas man only partakes of flesh foods after they have been camouflaged by cooking and by condiments.

"Man instinctively is not carnivorous," explains Dr. Latto. "...he takes the flesh food after somebody else has killed it, and after it has been cooked and camouflaged with certain condiments. Whereas to pick an apple off a tree or eat some grain or a carrot is a natural thing to do; people enjoy doing it; they don't feel disturbed by it. But to see these animals being slaughtered does affect people; it offends them. Even the toughest of people are affected by the sights in the slaughterhouse.

R.H. Weldon writes in No Animal Food:

"The gorge of a cat, for instance, will rise at the smell of a mouse or a piece of raw flesh, but not at the aroma of fruit. If a man can take delight in pouncing upon a bird, tear its still living body apart with his teeth, sucking the warm blood, one might infer that Nature had provided him with a carnivorous instinct, but the very thought of doing such a thing makes him shudder. On the other hand, a bunch of luscious grapes makes his mouth water, and even in the absence of hunger, he will eat fruit to gratify taste."

William S. Collens and Gerald B. Dobkens observe: "Examination of the dental structure of modern man reveals that he possesses all the features of a strictly herbivorous animal. While designed to subsist on vegetarian foods, he has perverted his dietary habits to accept food of the carnivore. It is postulated that man cannot handle carnivorous foods like the carnivore. Herein may lie the basis for the high incidence of arteriosclerotic disease."

Keith Akers in A Vegetarian Sourcebook (1983), responds to the argument that killing animals for food is natural:

"This is quite an admirable argument. It explains practically everything; why we do not eat each other, except under conditions of unusual stress; why we may kill certain other animals (they are, in the order of nature, food for us); even why we should be kind to pets and try to help miscellaneous wildlife (they are not naturally our food). There are some problems with the idea that an order of nature determines which species are food for us, but an examination of human history indicates the broad outlines of just such an order, though inhibitions against eating certain species may vary from culture to culture.

"The main problem with this argument is that it does not justify the practice of meat-eating or animal husbandry as we know it today; it justifies hunting. The distinction between hunting and animal husbandry probably seems rather fine to the man in the street, or even to your typical rule-utilitarian moral philosopher. The distinction, however, is obvious to an ecologist. If one defends killing on the grounds that it occurs in nature, then one is defending the practice as it occurs in nature.

"When one species of animal preys on another in nature, it only preys on a very small proportion of the total species population. Obviously, the predator species relies on its prey for its continued survival. Therefore, to wipe the prey species out through overhunting would be fatal. In practice, members of such predator species rely on such strategies as territoriality to restrict overhunting and to insure the continued existence of its food supply.

"Moreover, only the weakest members of the prey species are the predator's victims: the feeble, the sick, the lame, or the young accidentally separated from the fold. The life of the typical zebra is usually placid, even in lion country; this kind of violence is the exception in nature, not the rule.

"As it exists in the wild, hunting is the preying upon isolated members of an animal herd. Animal husbandry is the nearly complete annihilation of an animal herd. In nature, this kind of slaughter does not exist. The philosopher is free to argue that there is no moral difference between hunting and slaughter, but he cannot invoke nature as a defense of this idea.

"Why are hunters, not butchers, most frequently taken to task by the larger community for their killing of animals?...If any form of meat-eating is justified, it would be meat from a hunted animal."

In Animal Liberation, Australian philosopher Peter Singer writes:

"Killing an animal is in itself a troubling act. It has been said that if we had to kill our own meat we would all be vegetarians. There may be exceptions to that general rule, but it is true that most people prefer not to inquire into the killing of the animals they eat.

"Very few people ever visit a slaughterhouse; and films of slaughterhouse operations are rarely shown on television...Yet those who, by their purchases, require animals to be killed have no right to be shielded from this or any other aspect of the production of the meat they buy.

"If it is distasteful for humans to think about, what can it be like for the animals to experience it?"

Dr. Milton Mills' The Comparative Anatomy of Eating,

www.vegsource.com/veg_faq/comparative.htm

and the Physicians Committee for Responsible Medicine,

www.pcrm.org ,

argue that the optimal diet for humanity is a vegan diet. However, even if humans really are omnivores and not frugivores, the diet of natural omnivores is mostly (80 percent) plant food.