Tristan und Isolde is an immense dramatic-musical poem—an infinite song of love and death inspired by the 12th-century medieval legend of Celtic origin, as compiled by Gottfried von Strassburg. This tale became one of the cultural cornerstones of the Middle Ages and, in Wagner’s hands, a cultural revolution. Wagner weaves a rich constellation of references—ranging from Buddhism to the theatre of Calderón de la Barca and the philosophy of Schopenhauer—into a tension between opposing dualities: eros/thanatos, duty/instinct, and consciousness/subconscious. He presents a groundbreaking dramatic framework that anticipates modern psychology.