Daemons are good or benevolent nature spirits, beings of the same nature as both mortals and gods, similar to ghosts, chthonic heroes, spirit guides, forces of nature or the gods themselves (see Plato's Symposium). Walter Burkert suggests that unlike the Judeo-Christian use of demon in a strictly malignant sense, “[a] general belief in spirits is not expressed by the term daimon until the 5th century when a doctor asserts that neurotic women and girls can be driven to suicide by imaginary apparitions, ‘evil daimones’.