 John Baldwin's extensive study of Peter the Chanter and his circle underlines their social doctrines.Their teachings influenced the theological program of the Fourth Lateran Council.A group of Petrus' questions on the sacraments was compiled and published by Jean-Albert Dugauquier; see S"umma De Sacramentis et Animae Consiliis', Louvain, Louvain University Press, 1954–1957.