Vegetarianism, novelist and food critic Colin Spencer feels, has gotten a bad rap in world history. It certainly seems that meat-eaters have had all the fun: Roman generals munched on spit-roasted loins after every conquering battle, pre-Renaissance kings hefted bleeding joints as serfs scurried to fill their cups, and Camille Paglia entertained visiting reporters at Ruth’s Chris Steak House after the release of Sexual Personae. Meat reeks of power and prurient abundance, a heavy and meaningful aroma that a squash, however you slice it, just doesn’t emanate.

But Spencer would like to change all that with The Heretic’s Feast: A History of Vegetarianism. He’s determined to tie vegetarianism to social deviance, thus investing this ascetic creed—associated today with cholesterol counts and aging Victorians on the Road to Wellville—with the aura of transgression that he feels it deserves.

After all, for much of human history any sort of dietary deviance has garnered surprisingly harsh consequences. Feast demonstrates that vegetarianism in particular has long been a troublesome tendency, perceived in various times as everything from merely a crackpot scheme to grounds for execution. And however important technology, politics, and chance have been to the evolution of Westerners’ diets, these factors are only part of the story. Just as critical are our age-old, irrational beliefs about the significance of what we eat.

Spencer’s exploration of these beliefs is the most stimulating part of his book. Though it’s currently fashionable to root all neuroses in sexuality as we exercycle and munch carrot sticks, food has just as significant a role in stirring the pot of unconscious anxiety. Spencer provocatively suggests that the whole concept of taboo in human society originated with prehistoric dietary strictures. He points to the earliest times, when hunter-gatherers struggled to distinguish foods that would nourish from those that would kill. To survive, they had to know “the natural history of several thousand plants—where they grow and which part of the plant is edible at which time of year—and of several hundred animals—their feeding habits and migrating patterns.”

As this body of knowledge grew and was passed on, Spencer contends, people began to take a whole slew of unjustified but absolute prohibitions on certain foods for granted. Pretty soon these prohibitions came to be explained as the law of the gods, those capricious beings credited with controlling the change of seasons and thus the availability of sustenance. And once gods are involved, the whole question of what to eat becomes momentous.

This analysis of the meaning of food is fascinating, but unfortunately Spencer doesn’t stick to it. He can’t decide what type of history he wants to tell: a psychoanalytic one that explores the significance of flesh-eating and fleshliness in general, or a political/ ethical one linking vegetarianism and social dissidence. His book is vast and rambling, wandering from the ancient Greeks to India (though only briefly—despite cosmopolitan aspirations, he’s really much more comfortable in the West) to the European Renaissance and the Americas. And though he’s most compelling when analyzing the meanings behind various gustatory practices, he returns stubbornly to the task of establishing vegetarianism as a sign of philosophical sophistication and moral rectitude.

This leads to a tangle of internal contradictions, since of course the two motivations—“psychological,” for lack of a better word, and ethical—conflict fairly directly. Many prominent vegetarians, such as John Wesley, Leonardo da Vinci, and Adolph Hitler, were hardly crusaders for animal (or human) rights; they were merely following their own weird superstitions about flesh and blood. They were no more moral than the pig-slaughtering Greeks—or, for that matter, the cannibalistic Aztecs.

Take Pythagoras, a mathematician, mystic, and one of the earliest vegetarians. Spencer expounds at length on the importance of meat sacrifices in ancient Greece, and points to Pythagoras as a model of ethical restraint. In fact, though Pythagoras’ abstention was rooted in a kind of compassion—he believed that animals had souls, just like humans—it was as much due to a longing for immortality. The gods, it was believed, lived on the vapors from burnt sacrifices. By avoiding meat and eating only foods that he considered “aromatic,” like grains and fruit,Pythagoras thought he could recall past lives, live longer, and generally become rather godlike himself.

Spencer seems to think this strategy worked. He cites legends of Pythagoras’ ability to fly, heal the sick, and control wild oxen and boars. Relating a story in which the philosopher correctly guessed how many fish were in a net before setting the catch free, the author writes ingenuously that “Pythagoras, in his quiet, amiable way, obviously had a way with animals.”

This fawning treatment is applied to most of Feast‘s vegetarians. They come off as cerebral, ascetic types striving to master and transcend the body; meat-eaters, by contrast, wallow luxuriantly in its vicissitudes. Every time Spencer comes across a prominent philosopher who showed a modicum of concern for animals but wasn’t actually a vegetarian (Erasmus, Montaigne, and Sir Thomas More, for example), he throws up his hands: “Yet Montaigne [who opposed cruelty to animals] does not take the logical step of denouncing the slaughter of animals for the consumption of meat.” Many steak-eating dog-owners would contest this logic.

But it’s typical of Spencer’s relentlessly optimistic reasoning. Discussing the colonization of the Americas, he assumes that Europeans’ fascination with the “savages” they discovered in the New World equaled a respect for animal rights:

It was not such a huge leap for Christian Europe to go from considering the savage to considering the beast. In their natural state, it was thought, there was little difference between them, so if a savage could be noble it stood to reason that a beast could be too. But once you admitted that this potential existed, it was inevitable that you must treat the animal with kindness and concern. How then could you kill it for its meat?

Given the bloody results of the Europeans’ romanticizing, it’s not clear how Spencer can link compassion for animals with the refusal to kill them. He must do so to maintain his thesis that vegetarianism is tied to ethical purity, but one wonders why he didn’t simply abandon it in favor of a more clear-eyed analysis of the changing meanings of consumption and abstention.

Spencer’s history backfires in yet another way. Against a tapestry of barley soup and lofty philosophy, the frequent, forbidden whiffs of roasting meat trigger salivation rather than reflection. His descriptions of, say, the diet of Renaissance nobility—“brain in sharp sauce, then head of boar, young swans, capon, pheasant, heron, sturgeon, venison, suckling pigs, peacocks, cranes, rabbit and chickens”—inspire a kind of awe, maybe a bloated feeling, but certainly not the revulsion that he hopes for.

Serious vegetarians “have a natural horror of eating flesh,” but Spencer forgets that not everyone’s a vegetarian. Feast‘s readers, rather than taking up the celery stalk of reform, might work up an appetite for a thick, bloody T-bone.