Why do some cultures ban eating perfectly digestible, healthful and nutritious foods? In the realm of food anthropology, no subject is more mysterious and fascinating than that of food taboos, and no taboo is more fascinating than the one against meat that shows up around the world in diverse societies.

Tristram Stuart's thought-provoking book is not a global history of this taboo. Instead, it revolves around the vegetarian movement that began in 17th-century England -- the name first came into use in the 1840s -- and that remains strong today. But there is nothing narrow about the author's focus. Both scholarly and entertaining, The Bloodless Revolution is a huge feast of ideas -- ideas from India and France and America, from ancient Greece and Thoreau and Emerson, from Rousseau, Hobbes, the Kabbalah, the Old Testament, Descartes and Darwin, to name just a few of the better-known sources that weigh in on the meatless diet.

Vegetarianism illustrates the tremendous impact that India had on British culture but also the impact of the British on India. Mahatma Gandhi, Stuart tells us, didn't take up vegetarianism as a cause until he encountered the raw food movement, which dates back to the poet Shelley, while in London to study law. Gandhi embraced the diet -- he had rejected vegetarianism in his youth -- because he determined it was free of "himsa" or violence.

But the meatless diet couldn't be completely violence-free, for it also appealed to Adolf Hitler. Stuart points out that not only was Hitler a vegetarian but so were Himmler, Hess, Bormann and possibly Goebbels. They even argued about the purity of each others' diets, with Hess declining to eat meals cooked by Hitler's chef because the vegetables were not truly organic.

And these were not the only violent vegetarians. In the late 18th century, John Oswald advocated armed revolution in Britain while maintaining a vegetarian diet, convinced by his years in India that all killing was wrong. Therefore, he thought, killers must be killed. Although this sounds slightly mad, the same argument is frequently accepted as logic for capital punishment.

Fascinating as the array of moral, religious, philosophical, environmental and biological arguments in favor of vegetarianism is, the arguments against it are far more intriguing than even an inveterate meat-eater would imagine. For one thing, people long believed that life simply could not be sustained without meat. In 1654, the untimely death of Robert Norwood, an outspoken proponent of what today would be called a vegan diet, was widely believed to have been caused by malnutrition.

But do the animals that provide the meat that sustains life have souls, feelings? Could they be killed without remorse? Those questions long swirled around vegetarianism. Descartes, an advocate of vegetarianism for health reasons, nevertheless insisted that animals were incapable of thought or emotions. Even among those who otherwise admired Cartesian thinking, many took great offense at the suggestion that their cats and dogs were unfeeling beasts. In fact, as a reaction to Descartes, many philosophers started asserting that animals did have thoughts and feelings and therefore should not be consumed.

But we have to eat something. Today, many people accord feelings, emotions and thoughts to animals, but that has not stopped most of us from eating them. Even if we someday discovered that vegetables also have feelings, we would not starve ourselves because of it. In Hinduism, it is said that a true saint would live on nothing but air and that humans are incapable of such perfection.

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