prophetic divining of the future by observation of natural phenomena—particularly the behaviour of birds and animals and the examination of their entrails and other parts, but also by scrutiny of man-made objects and situations. The term derives from the official Roman augurs, whose constitutional function was not to foretell the future but to discover whether or not the gods approved of a proposed course of action, especially political or military. Two types of divinatory sign, or omen, were recognized: the most important was that deliberately watched for, such as lightning, thunder, flights and cries of birds, or the pecking behaviour of sacred chickens; of less moment was that which occurred casually, such as the unexpected appearance of animals sacred to the gods—the bear (Artemis), wolf (Apollo), eagle (Zeus), serpent (Asclepius), and owl (Minerva), for instance—or such other mundane signs as the accidental spilling of salt, sneezing, stumbling, or the creaking of furniture.

The prophetic art is age-old; the practice of augury is well substantiated in the Bible. Cicero's (Cicero, Marcus Tullius) De divinatione (Concerning Divination), dated probably 44 BC, provides the best source on ancient divinatory practices. Both he and Plato distinguish between augury that can be taught and augury that is divinely inspired in ecstatic trance. In China for millennia many have sought the counsel of the I Ching (Yijing) (“Book of Changes”) before taking important action. This book interprets the hexagram created by the tossing of yarrow stalks. Among the vast number of sources of augury, each with its own specialist jargon and ritual, were atmospheric phenomena (aeromancy), cards (cartomancy), dice or lots (cleromancy), dots and other marks on paper (geomancy), fire and smoke (pyromancy), the shoulder blades of animals (scapulimancy), entrails of sacrificed animals (haruspicy), or their livers, which were considered to be the seat of life (hepatoscopy).