Pythagoras: The First Vegetarian of the Ancient World and a Contemporary of the Buddha?

Written by Jennafer Duerden, 3rd February 2026

Most people recognize Pythagoras for his mathematical theorem describing relationships in right-angled triangles. However, his philosophical contributions to vegetarianism represent an equally significant legacy. Over 2,500 years ago, Pythagoras became one of the earliest documented advocates for a plant-based diet in Western civilization, establishing a school of thought that would influence numerous ancient Greek and Roman scholars.

Vegetarianism appears ubiquitous in contemporary society, with plant-based alternatives filling supermarket shelves and major corporations offering meatless options. Yet this modern phenomenon obscures vegetarianism’s ancient roots. One might assume the practice is recent, especially given historical associations with animal sacrifice and meat consumption in antiquity. Was Pythagoras a revolutionary reformer whose ideas resonate through modern movements, or simply an outlier whose teachings faded after his death?

The Buddha, according to Buddhist tradition, lived from 563 to 483 BC—making him Pythagoras’s contemporary. Pythagorean and Buddhist philosophies share notable perspectives on meat consumption, suggesting possible cross-cultural influence through Greek-Indian contact. Yet Buddhism differs fundamentally from Platonic thought regarding the soul’s nature.

The primary challenge in understanding Pythagoras’s vegetarian beliefs stems from the absence of written records by him or his contemporaries. Accounts of Pythagoras emerged approximately 150 years after his death. By the third century AD, mythological embellishments obscured his actual teachings, while numerous forged texts appeared during the first century BC. Therefore, we must examine later philosophers—Socrates, Plato, and Aristotle—who discussed his lifestyle and philosophical positions.

A Brief Introduction to the Life of Pythagoras

Pythagoras (approximately 570-495 BC) was an Ionian Greek philosopher and polymath excelling in diverse fields. Around age thirty, he traveled to Croton in southern Italy, establishing an ascetic communal school combining political, religious, and philosophical instruction.

Mythology deeply surrounds Pythagoras’s legacy. Ancient sources credited him with discoveries spanning musical tuning, proportional theory, Earth’s sphericity, and astronomical observations about Venus. Modern classical scholars generally attribute many discoveries to predecessors or contemporaries rather than Pythagoras himself. He is more securely associated with ideas concerning metempsychosis—the transmigration of souls between bodies after death.

Despite mythological accretion, Pythagoras profoundly influenced Plato and earned admiration from later scientists including Kepler, Copernicus, and Newton. Ovid’s portrayal and Porphyry’s later Roman Neoplatonic interpretations significantly shaped modern vegetarian movements.

Socrates, Plato, and Aristotle

Key evidence for Pythagorean thought derives from fifth- and fourth-century BC philosophers Socrates, Plato, and Aristotle. Born shortly after Pythagoras’s death, Socrates established himself as Western philosophy’s father, profoundly shaping his pupil Plato. Plato appears heavily influenced by Pythagorean philosophy, providing valuable insights into Pythagoras’s animal attitudes. Conversely, Aristotle—Plato’s student—held markedly different views on animal intelligence, exerting powerful and arguably detrimental influence on Western animal welfare perspectives for centuries.

Greek intellectuals following Pythagoras’s death debated whether animals possessed rationality and deserved treatment equal to humans. Such questions regarding animal reason and purpose remained central to philosophical discourse.

The Downfall of Society

Our understanding of Socrates comes exclusively through Plato’s writings. In The Republic, Plato presents Socrates envisioning a utopian, meat-free society: “The work-people will live, I suppose, on barley and wheat, baking cakes of the meal and kneading loaves of the flour… We shall also set before them a dessert, I imagine, of figs, peas and beans… And thus passing their days in tranquillity and sound health, they will, in all probability, live to a very advanced age and, dying, bequeath to their children a life in which their own will be reproduced.”

Socratean philosophy argues that such societies inevitably desire luxuries, and these very indulgences—particularly meat—precipitate decline: “Further still, we shall want swine-herds likewise… and many other sorts of herds likewise, if any one is to eat the several animals… shall we not then, in this manner of life, be much more in need of physicians than formerly? Must we not then encroach upon the neighbouring country, if we want to have sufficient for plough and pasture? Shall we afterwards fight? Then we have found the origin of war.”

Here luxury food consumption directly connects to disease, territorial expansion, and ultimately conflict—themes powerfully resonating with later meat consumption critiques.

Animals as Rational Creatures

Plato frequently emphasized reason over sensation and perception. His animal consciousness views prove complex and sometimes contradictory, ultimately reaching a middle position. While maintaining animals lack human-level rationality, he considered them sentient beings.

Plato asserted that animals cannot “reflect on or analyse that which they see,” distinguishing human consciousness. Yet in Timaeus, he concedes “everything that partakes of life may be truly called a living being,” extending this even to plants. Though such beings lack rationality, they possess sensation, pleasure, and pain, qualifying as living entities.

Throughout his works, Plato attributes animals with human-like moral or cognitive qualities, or describes humans as “beast-like.” In Laches, he discusses “thoughtless boldness” shared by humans and animals. In Laws, he praises animals maintaining monogamous relationships as “holy and just, remaining faithful to their first contracts of friendship.” Plato repeatedly references soul migration between species, reinforcing spiritual kinship between humans and animals—a theme closely aligned with Pythagorean thought.

Plato and Metempsychosis

Pythagoras believed in metempsychosis, or soul transmigration—a doctrine central to many Indian religions, including Hinduism. According to this philosophy, human souls may inhabit animal bodies after death. Consuming animal flesh therefore becomes morally equivalent to cannibalism.

As Porphyry explains: “If it should appear, according to Pythagoras, that they are allotted the same soul that we are, he may justly be considered impious who does not abstain from acting unjustly towards his kindred.”

Pythagoras’s principle transcends mere dietary choice; it represents a moral imperative grounded in recognizing shared life and shared soul. By abstaining from animal flesh, one honors life’s continuity and respects the possibility that encountered beings might have been—or might become—human. This ethical stance frames vegetarianism not as personal preference or health choice, but as justice and spiritual responsibility. Later thinkers, including Porphyry and Roman Neoplatonists, emphasized this principle in writings linking it to virtue, life’s sanctity, and soul cultivation. Pythagorean vegetarian commitment emerges as both philosophical and practical expression of their metaphysical worldview, illustrating how diet, ethics, and soul belief become inseparably intertwined.

Contrast with Buddhism: Transmigration of Souls and Saṃsāra

Buddhist tradition dates the Buddha’s life from 563 to 483 BC, making him Pythagoras’s contemporary. While Pythagorean and Buddhist perspectives on meat consumption share similarities, Buddhism diverges sharply in understanding the soul. Rather than positing an unchanging soul transmigrating between bodies, Buddhism teaches saṃsāra—a continuous rebirth cycle driven by consciousness and karma, without permanent self.

This distinction appears in dialogue between monk Nāgasena and King Milinda:

“Suppose a man, O king, were to light a lamp from another lamp. Can it be said that the one transmigrates from, or to, the other?”

“Certainly not.”

“Just so, great king, is rebirth without transmigration.”

Despite this doctrinal difference, Pythagorean and Eastern philosophies’ parallels remain striking. Both traditions challenge human exceptionalism assumptions and question suffering infliction’s moral permissibility on living beings. In each case, ethical behavior connects closely to understanding life as interconnected and cyclical rather than linear and anthropocentric. Whether articulated through soul transmigration or rebirth cycles, these philosophies encourage restraint, compassion, and action consequence awareness beyond immediate human spheres.

The conclusion that eating meat resembles cannibalism appears echoed in Buddha’s words to Mañjuśri:

“There is not a single being, wandering in the chain of lives in endless and beginningless saṃsāra, that has not been your mother or your sister. An individual, born as a dog, may afterward become your father. Each and every being is like an actor playing on the stage of life. One’s flesh and the flesh of others is the same flesh. Therefore the Enlightened Ones eat no meat.”

Aristotle and the Hierarchy of Life

Although Plato’s student, Aristotle held far less ambiguous views on animal rationality and humanity’s moral relationship with animals. Regarded as biology’s founder, Aristotle wrote extensively on animals and the soul’s nature. He proposed three soul types: the nutritive soul (nourishment, growth, reproduction), the sensitive soul (perception, movement), and the rational soul (mind).

In De Anima, Aristotle argued that plants possess only nutritive soul, animals possess nutritive and sensitive souls, and humans alone possess all three. Animals therefore exclude themselves from rational thought. This view reinforces in The History of Animals, where Aristotle asserts that while many animals possess memory and learning capacity, only humans deliberately recall the past and engage in rational deliberation. Aristotle thus established a hierarchical life model wherein animals exist for human use. By denying animals rationality and true sentience capacity, he provided powerful philosophical justification for meat consumption—starkly contrasting Pythagoras, profoundly shaping Western thought for centuries.

The Influence on Modern Life

Aristotle significantly influenced medieval Christian ethics and, through them, prevailing Western animal attitudes today. While Aristotle acknowledged that “in all animals there is something natural and beautiful,” one wonders how vegetarianism attitudes might have developed had he adopted more Platonic animal sentience views.

This ancient Greek animal rationality debate continues presently. Despite growing animal intelligence evidence—from corvid funeral-like behaviors to elephants’, lions’, and ravens’ complex social reasoning—many argue animals lack higher-order cognition and thus subordinate themselves to human interests. Modern vegetarianism often emphasizes environmental or health concerns more heavily than animal welfare, which remains, for many, a fringe ethical position.

Factory farming, driven by insatiable meat demand, contributes to pollution, environmental degradation, and climate change while exacerbating health crises including heart disease and obesity. Humanity’s persistent self-elevation above all life forms, combined with endless luxury appetite, has produced war, famine, genocide, and widespread suffering. In this sense, we may inhabit precisely the decay and decline period Socrates and Plato predicted—decline potentially avoidable through greater Pythagorean vision heed.

Pythagoras’ Legacy

Pythagoras’s vegetarianism advocacy represents not merely dietary preference but a moral position grounded in broader metaphysical worldview. By rejecting animal consumption, Pythagoreans sought harm minimization and spiritual purity maintenance, reflecting beliefs that violence against living beings ultimately corrupts human souls. Although later Western philosophy largely abandoned this outlook favoring hierarchical life conceptions, Eastern tradition vegetarian ethics persistence suggests such ideas were neither marginal nor unsustainable.

In the modern world, where industrialized farming and environmental degradation have intensified humanity’s life form impact, these ancient perspectives gain renewed relevance. Philosophical questions raised by Pythagoras and intellectual descendants—concerning animal moral status, soul nature, and humanity’s natural order place—continue resonating today. While imposing contemporary ethical frameworks onto antiquity would prove anachronistic, revisiting Pythagorean vegetarianism invites reflection on whether Western philosophy may have overlooked a more compassionate and sustainable path.

Ultimately, Pythagoras’s legacy extends far beyond geometry. His ethical thought influence, particularly regarding animal treatment, reveals alternative philosophical traditions challenging long-standing dominance, consumption, and moral responsibility assumptions. In this sense, Pythagoreanism-associated vegetarian ideals represent not obscure ancient sect relics, but enduring conversation participants about appropriate human living.

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