period in his life. More recently, however, impressive evidence has come to light which points convincingly to a later dating.7 It now seems almost certain that the commentary was composed at Naples between October 1272 and June 1273—during the period, in other words, immediately prior to Thomas’s death. It is hard to exaggerate the importance Aquinas gave to the book of Psalms, and to the value, therefore, of a close exegetical reading of the text. ‘Materia est universalis’, he declared in the introduction