Abstract
Over the last decades, the Commissio Leonina has built up a very strong reputation. Editions such as theSentencia libri De anima and the Sentencia libri de sensu et sensato by R.-A. Gauthier or the commentaries on Boethius by P.-M. Gils, L.-J. Bataillon and C.A. Grassi have set new philological standards, not only because of their fine critical introductions and excellent reconstructions of Thomas Aquinas’ texts, but also because of their rich and accurate apparatus fontium. It may be doubted, however, whether the present edition of De spiritualibus creaturis by Father J. Cos lives up to the same high standards