In 1823, Alessandro Manzoni engaged a continuing debate over the merits of ‘Aristotelian’ unities of time and place with his Lettre à M. C*** sur l'unité de temps et de lieu dans la tragédie, a manifesto that synthesises and amplifies earlier polemics by Berchet, Pellico and Visconti. Dramatic expression, coherence and realism, Manzoni argued, are best served by giving priority to unity of action while ignoring the traditional restrictions of time and setting. Although discontinuities might occur between adjacent scenes, the focus on cause and effect and the exclusion of unrelated incidents would provide a coherence that had previously depended on physical and temporal proximity. Manzoni suggested that formal preconceptions be set aside and the action allowed to shape dramatic design. Characters could be introduced throughout a play rather than together in the first act, their motivations and goals allowed to evolve as the situation unfolds. These shifts would encourage writers to cultivate motifs other than love intrigues, which had traditionally held sway because they took little time to develop. In particular, historical plays could enact all important events instead of only the climax, and depict true causes and resolutions rather than ones invented to fit conventional constraints.