In Greek literature, the earliest magical operation that supports a definition of magic as a practice aimed at trying to locate and control the secret forces (the sympathies and antipathies that make up these forces) of the world ("physis" ) is found in Book X of the "Odyssey" (a text stretching back to the early 8th century BCE). Book X describes the encounter of the central hero Odysseus with the Titan Circe, "She who is sister to the wizard Aeetes, both being children of the Sun...by the same mother, Perse the daughter of the Ocean," on the island of Aeaea. In the story Circe's magic consists in the use of a wand against Odysseus and his men while Odysseus's magic consists of the use of a secret herb called moly (revealed to him by the god Hermes, "god of the golden wand") to defend himself from her attack. In the story three requisites crucial to the idiom of "magic" in later literature are found: