The Traite de l'uniformite et de l'amelioration de la liturgie (Treatise on the Uniformity and Improvement of the Liturgy) is a plea for a reasoned reform of the catholic Liturgy. By reinterpreting the Tridentine decrees in the light of Tradition, of reason but also of the French Revolution, the famous abbe Gregoire defines what would be a perfect catholic Liturgy.