Note 258 — BOOK III

C. Schmidt, op. cit., after a detailed comparison of passages, concludes that Isidore did not obtain his material for De Musica from Cassiodorus or Augustine, but that all three go back independently to an original work produced by an unknown Christian writer. However, the numerous identical passages in Cassiodorus and Isidore would indicate that the latter had used the former at least as a guide in plagiarism. See Schmidt, pp. 26–52, and compare Dressel, De Isidori Originum Fontibus (Turin, 1874), pp. 5 and 6.