Jason or the return of the Sinner. A sketch of Argonautic mythology. The three misdeeds committed by Jason after leaving Colchis (the murder of Absyrtus then Pelias, the repudiation of Medea) may be interpreted using the « three sins of the warrior » elaborated by Georges Dumézil, and attested in Greece by the legend of Heracles. It was in India, however, that the closest correspondances are to be found : in the gesture of the god Indra, and especially in the "Rāmāyana" as analyzed by Daniel Dubuisson. These comparisons enable to formulate new hypotheses about the signification of characters and their role in the structure of the mythical narrative.Les trois fautes que commet Jason après son départ de Colchide (meurtres d'Apsyrtos puis de...