Donald McGrady
La ingratitud vengada, praised by Cervantes in Don Quijote I, 48, was written by his archenemy Lope de Vega. It treats the same subject as Lope's La Dorotea, that is, his love affair with Elena Osorio. What has not been appreciated is that Cervantes' reason for praising this bad play is that it portrays Lope in a very negative light. By citing it, Cervantes indulges in the irony of having his adversary condemn himself.