Was he a theologian (or interested in theology)? Did Gratian borrow Augustinian texts from the Liber divinarum sententiarum?
Milano, Biblioteca Ambrosiana Y 43, fol. 7r
Giuseppe Mazzanti, Guarnerius Iurisperitissimus. Liber divinarum sentiarum. Testi, Studi, Strumenti 14. Spoleto: Centro Italiano di Studi sull’Alto Medioevo, 1999.
Los Angeles, Getty Museum, Ludwig XIV.2, fol. 83r
Gratian, Decretum Causa 1