Great Chain of Being

Aristotle, and later the Stoics, believed the world was populated by an infinity of beings arranged hierarchically according to their complexity and perfection, from the barely living to the merely sentient, the rational, and the wholly spiritual. In this Great Chain of Being, as it came to be known, all forms of life were represented as existing for the sake of those forms higher in the chain. Among corporeal beings, humans, by dint of their rationality, occupied the highest position.

The Stoics, insisting on the irrationality of all nonhuman animals, regarded them as slaves and accordingly treated them as contemptible and beneath notice. Aggressively advocated by St. Augustine (354–430), these Stoic ideas became embedded in Christian theology. They were absorbed wholesale into Roman law—as reflected in the treatises and codifications of Gaius (fl. 130–180) and Justinian (483–565)—taken up by the legal glossators of Europe in the 11th century, and eventually pressed into Western law.

The most important consequence of this view is that animals have long been categorized as “legal things,” not as “legal persons.” Whereas legal persons have rights of their own, legal things do not. They exist in the law solely as the objects of the rights of legal persons—e.g., as things over which legal persons may exercise property rights.

Meanwhile, arguments that urged respect for the interests of animals nearly disappeared, and animal welfare remained a relative backwater of philosophical inquiry and legal regulation until the final decades of the 20th century.

The Great Chain of Being became one of the most persistent and powerful ways of conceiving the universe, dominating scientific, philosophical, and religious thinking until the middle of the 19th century.