Poussin considers himself a pictor poetic, expressing his art in a mute language. He demands that his audience read his works and decipher his visual metaphors. According to his biographers, Poussin adopts an unusual method of work by creating a kind of a model of a stage, thus taking on the simultaneous role of both stage director and decorator. In his theory of modes Poussin recommends adapting the style of the setting to the subject-matter. His formulation is largely influenced by Vitruvius' theory, later echoed in the Renaissance theory of Art and scenography (Alberti and later Serlio). According to these principles the sublime and noble setting of the scena tragica the eternal and ideal city, should be adopted for heroic and historical subjects. Poussin, a nonconformist creator, however, could not be content with merely adopting the scena tragica setting repeatedly. His changes and deviations from the Renaissance formulations become expres­sive means (as in the Massacre of the Innocents), and visual metaphors in translating his moralistic ideas. By inserting contemporary architectural elements taken from the scena comica into the ideal city setting, Poussin actualizes the remote time and signs of transience and ephemeral life now become carved in the decor. Thus architectural principles become speaking elements in Poussin's mute language, translating and reflecting his moralistic approach to art.