Vegetarianism is the theory and practice of voluntary non-consumption of the flesh of any animal, including sea animals.
The known history of vegetarianism begins civilizations of ancient India, Egypt, and Greece. Religious groups in Egypt (~ 3,200 BCE - Before Current Era) practiced abstinence from flesh and from wearing animal-derived clothing. The earliest records of vegetarianism as a concept and practice amongst a significant number of people concern the India and Greece civilizations. In both instances the diet was closely connected with the idea of nonviolence toward animals (Ahimsa in India), and was promoted by religious groups and philosophers. In the ancient Vedic period vegetarianism was encouraged, but eating some kinds of meat was allowed by law.
Abstention from meat was central to such early philosophies and religions as Hinduism, Brahinanism, Zoroasterianism and Jainism, based on doctrines of non-violence and respect for all life forms. Vegetarianism was encouraged in Upanishads and mentioned in Rig Veda. Vegetarianism was and still is mandatory for the yogis (practitioners of Yoga). Vegetarianism is central to Buddhism, for compassion to all living creatures. Parshva, the earliest Jain leader (Tirthankara, 8-7 centuries BCE) preached nonviolence, and the principle of nonviolence toward animals was an established rule in Jain and Buddhist societies in 6th century BCE. The Indian king Asoka (304 - 232 BCE) converted to Buddhism and ended animal sacrifices, the kingdom became vegetarian.
Chinese Buddhism and Taoism require that monks and nuns eat an egg free vegetarian diet. Since abbeys were usually self-sufficient, in practice this meant they ate a vegan diet. Many religious orders also avoid harming plant life by avoiding root vegetables (elements of fruitarianism). In Chinese folk religions people often eat vegan on the 1st and 15th of the month, as well as the eve of Chinese New Year. This is similar to the Christian practice of lent and not eating meat on Friday.
In 675, the use of livestock and the consumption of some wild animals (horse, cattle, dogs, monkeys, birds) was banned in Japan by Emperor Temmu, due to the influence of Buddhism. Then in 737, the Emperor Seimu approved the eating of fish and shellfish. During the 1200 years till 19th century, Japanese people enjoyed vegetarian-style meals, serving fish only on special occasions.
Homer mentioned vegetarians in Odyssey, Herodotus mention the Lotophagi (Lotus-eaters) - indigenous people of the North African coast, who lived on nothing but the fruits of a plant called lotus. See Lotus-Eaters Lotophagi. Diodorus Siculus tells about vegetarian peoples or tribes in Ethiopia
The earliest reliable evidence for vegetarian theory and practice in Greece dates from the 6th century BCE. The Orphics, a religious movement spreading in Greece at that time, and Pythagoras (580 BCE, a philosopher and religious leader known for his contributions to mathematics and as the first to admit women to his intellectual circle on equal terms) and his followers, abstained from the flesh of animals. Pythagoreans did not always practice strict vegetarianism, but their inner circle did. Both Orphics and strict Pythagoreans also avoided eggs and shunned the ritual offerings of meat to the gods. In the 5th century BCE the philosopher Empedocles distinguished himself as a radical advocate of vegetarianism specifically and of respect for animals in general. Some prominent Stoics with the founder of Stoicism Zeno, Ovid, and Seneca, refrained from eating animals. Ovid also praised the Pythagorean ideal of universal nonviolence (Metamorphoses).
In the Platonic Academy the school heads Xenocrates and probably Polemon pleaded for vegetarianism. In the Peripatetic school Theophrastus, Aristotle's immediate successor, supported it too. Some of the prominent Platonists and Neo-Platonists in the age of the Roman Empire lived on a vegetarian diet, including Plutarch (temporarily), Apollonius of Tyana, Plotinus, and Porphyry. Followers of the Cynic School had extremely frugal way of life and practically meatless diet. In The Republic, Plato’s character Socrates said that the ideal city was a vegetarian, because meat was a luxury leading to decadence and war. Plutarch (~ 46 CE) wrote Essay on Flesh Eating. Porphyry (~ 232 CE) wrote On Abstinence From Animal Food, , the most elaborate ancient pro-vegetarian text known to us. Apollonius was a strict vegetarian.
Many early Christians were vegetarian such as Clement of Alexandria, Origen, John Chrysostom, Basil the Great, and others. Some early church writings suggest that Matthew, Peter & James were vegetarian. The historian Eusebius writes that the Apostle "Matthew partook of seeds, nuts and vegetables, without flesh."
In late antiquity and in the Middle Ages many monks and hermits renounced meat-eating in the context of their asceticism. The most prominent of them was St Jerome (419 CE). The most influential theologians though, St Augustine and St Thomas Aquinas, emphasized that man owes no duties to animals.
After the Christianization of the Roman Empire in late antiquity, 4th-6th centuries of Current Era (CE), vegetarianism nearly disappeared from Europe. Several orders of monks in medieval Europe restricted or banned the consumption of meat for ascetic reasons, but none of them abstained from the consumption of fish: these monks were pescetarians.
In 3-10th centuries, Manicheanism, a major religious movement, was another philosophy against animal slaughter. Their elite group called Electi were Lacto-Vegetarians for ethical reasons and abode by a commandment which strictly banned killing. Common Manicheans Auditores obeyed looser rules of nonviolence. Manicheans, non-violent vegetarian ascetics, were painted as fanatical deviants, feared, loathed and frequently persecuted by the established church. The vegetarian Bogamils, a christian sect living in what is now Bulgaria, had two notable vegetarians: St David, Patron Saint of Wales, and St Francis of Assisi. Christian dualist Cathars also despised the consumption of meat. Many intellectual dissidents, such as the Encratites, the Ebionites, and the Eustathians abstained from meat too.
In Greek-Orthodox Christianity (Greece, Cyprus, Russia, Serbia and other Orthodox countries), adherents eat a diet completely free of animal products for fasting periods (except for honey).
Vegetarianism was to reemerge somewhat in Europe during the Renaissance as a philosophical concept based on an ethical motivation. Among the first celebrities who supported it were Leonardo da Vinci (1452–1519) and Pierre Gassendi (1592–1655). Long-lived dietitian Cornaro (1465-1566) was vegetarian. John Locke (1632–1704) argued that animals were intelligent.
In the 17th century the paramount theorist of the meatless diet was the English writer Thomas Tryon (1634–1703).
In the United States, there were small groups of Christian vegetarians in the 18th century. The best known of them was Ephrata Cloister in Pennsylvania. Benjamin Franklin, one of the founders of the United States, became a vegetarian at the age of 16, but later reluctantly returned to meat eating. He later introduced Tofu to America in 1770. Colonel Thomas Crafts Jr., who read The Declaration of Independence in Boston in 1776, was a vegetarian.
A prominent advocate of an ethically motivated vegetarianism in the early 19th century was poet Percy Bysshe Shelley (1792–1822).
In England, Reverend William Cowherd advocated vegetarianism and was one of the philosophical forerunners of the Vegetarian Society, the first vegetarian society of the modern western world. It was founded in 1847 by the 140 participants of a conference at Ramsgate and by 1853 had 889 members, by the end of the century - almost 4,000 members. Prominent female vegetarians were Elizabeth Horsell, author of a vegetarian cookbook and lecturer, and Jane Hurlstone, who advocated animal welfare. In 1895, The Women's Vegetarian Union was established by Alexandrine Veigele.
Margaret Fuller also advocated for vegetarianism in her writing in 1845. Charlotte Perkins Gilman desired to have a vegetarian society in her utopia Herland (1915). Frances Power Cobbe, a co-founder of the British Union for Abolition of Vivisection, identified as a vegetarian.
In the United States, Reverend William Metcalfe (1788–1862), who preached vegetarianism, and Sylvester Graham were among the founders of the American Vegetarian Society in 1850. Ellen G. White, one of the founders of the Seventh-day Adventist Church, became an advocate of vegetarianism, and the Church has recommended a meatless diet ever since.
In Russia, writer Leo Tolstoy (1828–1910) was the most famous supporter of vegetarianism.
In Germany, the politician Gustav Struve (1805–1870) was a leading figure in the initial stage of the vegetarian movement. He was inspired by Rousseau's Émile. Many vegetarian associations were founded in the Food Reform movement.
The International Vegetarian Union, a union of the national societies, was founded in 1908. In the Western world, the popularity of vegetarianism grew during the 20th century as a result of nutritional, ethical, and more recently, environmental and economic concerns. Henry Stephens Salt (1851-1939) and George Bernard Shaw (1856-1950) were famous vegetarian activists.
The Indian concept of nonviolence had a growing impact in the Western world. The model of Mahatma Gandhi, a strong and uncompromising advocate of nonviolence toward animals, contributed to the popularization of vegetarianism in Western countries.