People tend to think of divination as a process concerned with the future and with such questions as "Will I marry?" and "Will I be rich?" But in ancient Greece and Rome, as in many other cultures, divination was predominantly concerned with discerning the will of the gods and other superhuman entities (e.g., demons, ghosts) and then learning how to bring oneself into harmony with them. Thus, the enquirer might try to find out why famine was harming his city: Had the dead not received the cult that was due them? Was a god being ignored? Alternatively, an enquirer might ask a god's advice: shall we institute a new political system in Athens? In the latter sort of cases, the enquirer typically presented a detailed plan to the god and then asked for his or her approval, rather than giving the...