This essay presents the initial hypothesis of the diversity of cases shown by Lope de Vega's theatre, that multiply perspectives and different endings from the same basic types of conflicts and designs, and tries to verify them with contemporary thought. This diversity is related with a certain type of discourse that has begun to spread out in the very beginning of the Renaissance and was gradually displacing the pre-eminence of universal principles (neo-platonic, or neo-aristotelic and scholastic) for an invitation to casuistic analysis, an ethical modality applied that chose the concrete analysis of the concrete situation in front of the universally required dogmas. A type of discourse that can be detected at the doctrinarian texts of that time. We analyze this kind of discourse trough the satire made by Pascal, in his Provinciales, of the Casuistic treatises of Jesuits (white and black), and his legitimization and put into practise by Montaigne in his Essays (black and white), to establish finally the convergences between the Montaigne's and Lope's way of working, in the framework of thought that begins to establish the bases of an immanent, pragmatic, relative comprehension, based on the personal experience, and partially separated of the sacred, that announces the modern times.