Etrusca disciplina

The Etrusca disciplina was a complex system of divination practiced by the ancient Etruscans, which heavily influenced Roman practices. This pseudoscience involved interpreting the will of the gods through various means, most notably by examining the entrails of sacrificial animals, particularly the liver and gallbladder. Haruspices, the Etruscan diviners, also interpreted natural portents like thunder and lightning, as well as unusual births, and prescribed rituals to appease the gods.12

The Etruscans believed the gods manifested their will in all aspects of the natural world and human creations. They developed elaborate lore and rituals, reportedly taught by a prophet named Tages, to understand these divine messages. This system included observing lightning and celestial phenomena, and interpreting prodigies. While adopted by the Romans, haruspicy never became a formal part of Roman state religion but rather a body of expert advisers.231