15. Everyone from Roman generals to Alexander the Great believed that reading animal entrails could show what the future had in store
In a number of ancient civilizations, animals were killed and their entrails examined as a means of predicting the future. This grisly practice was especially common in Ancient Rome. For hundreds of years, sheep and poultry were killed, with their insides then laid out on clean slabs or marble or stone and examined for clues as to what the future might hold. The Romans even had special devices called haruspices. These were usually shaped like a liver, with inscriptions on different parts of the organ advising what marks found here meant. Doctors even used this method to see whether their patients would live or die.
Famously, Alexander the Great also used this method. He would often consult his favorite seer, a Greek named Aristander, before going into battle. Before the siege of Tyre, for example, Alexander was told that the entrails showed that the city would be taken by the end of the month. Since it was already the last day of the month when the prediction was made, the warlord was skeptical. He even had the calendar put back two days. However, he needn’t have bothered. Tyre was taken within 24 hours – the entrails had been correct after all!