In the story of Damon and Pythias, Damon agrees to take the place of his friend Pythias, who is sentenced to death, while Pythias returns home to settle his affairs. Pythias promises to return, but Dionysus, the ruler of the story, demands some security. In the end, Pythias stays faithful to his friend and returns, and Dionysus pardons both men.
The story is renowned for the level of loyalty between Damon and Pythias. Damon offers himself, knowing full well that if Pythias does not return, he will be put to death in his place. Despite the doubts of everyone in the kingdom, Pythias returns to accept his fate as Damon knew he would.
The story of Damon and Pythias is one of the Pythagorean Mysteries. The Pythagorean Mysteries are a set of stories written in the early 20th century concerning Pythagoras and his followers. They were originally presented as children's stories, though little of the content is considered appropriate for children in contemporary society. Furthermore, although the mysteries are written in support of Pythagoras, the writings of Pythagoras do not actually still exist. The story of Damon and Pythias, therefore, is more of an illustration of Pythagoras's philosophy. The essence of the tale is that friends honor each others' commitments.