Hylas. In classical mythology, Hylas was a youth who served as Heracles' companion and servant, as well as lover. His abduction by water nymphs was a theme of ancient art, and has been an enduring subject for Western art in the classical tradition. In Greek mythology, Hylas was the son of King Theiodamas of the Dryopians and the nymph Menodice. In some accounts, his father was Euphemus or King Ceyx of Trachis. After Heracles killed Theiodamas in battle, he took on Hylas as arms bearer and taught him to be a warrior, and in time the two fell in love. The poet Theocritus wrote about the love between Heracles and Hylas: We are not the first mortals to see beauty in what is beautiful. No, even Amphitryon's bronze-hearted son, who defeated the savage Nemean lion, loved a boy, charming Hylas, whose hair hung down in curls. And like a father with a dear son he taught him all the things which had made him a mighty man, and famous. Heracles took Hylas with him on the Argo, making him one of the Argonauts. Hylas was kidnapped by nymphs of the spring of Pegae, Mysia when they fell in love with him, and he vanished without a trace. This greatly upset Heracles, who was his lover, so he along with Polyphemus searched for a great length of time. The ship set sail without them. According to the Latin Argonautica of Valerius Flaccus, they never found Hylas because the latter had fallen in love with the nymphs and remained to share their power and their love. The story of Hylas and the nymphs is alluded to in Book 3 of Edmund Spenser's The Faerie Queene, Canto XII, Stanza 7: Or that same daintie lad, which was so deare To great Alcides, that when as he dyde He wailed womanlike with many a teare, And every wood, and every valley wyde He fild with Hylas name; the Nymphes eke Hylas cryde. Hylas is also mentioned in Christopher Marlowe's play Edward II: Not Hylas was more mourned for of Hercules / Than thou hast been of me since thy exile, and in Oscar Wilde's The Picture of Dorian Gray, Chapter 11. .and gilded a boy that he might serve at the feast as Ganymede or Hylas. Hylas is referred to in Chapter 18 of Kingsley's Hypatia, when the Prefect Orontes, rescued by the Goths, is taken for safety into a house largely populated by women, and fancies humself as A second Hylas. Hylas is the name of one of the two characters in George Berkeley's Three Dialogues between Hylas and Philonous. He represents the materialist position against which Berkeley argues. In this context, the name is derived from ὕ, the classical Greek word for matter. Stanislaw Lem adopted these characters in his 1957 non-fiction, philosophical book, Dialogi.