The prediction of future events. The etymology of the word is ultimately Greek, from pro- "before" plus the root of phanai "speak", i.e."speaking before" or "foretelling", but prophecy often implies the involvement of supernatural phenomena, whether it is communication with a deity, the reading of magical signs, or astrology. It is also used as a general term for the revelation of divine will. Throughout history, people have sought knowledge of future events from special individuals or groups who were thought to have the gift of prophecy, such as Oracles at Delphi in ancient Greece. Cultures in which prophecy played an important role include the North American Indians, Mayans, Celts, Druids, Chinese, Chaldeans, Assyrians, Egyptians, Hindus, Hebrews, Tibetans, Greeks, and many in the Christian tradition, among others.