dialogues, describing the Monophysites as beggars passing off their doctrines gathered by scraps from diverse heretical sources and himself as the orthodox. The work is interspersed with lengthy florilegia (anthologies of patristic citations), which may be the reason for its preservation. These florilegia provide evidence of Theodoret's considerable learning, with 238 texts drawn from 88 works, including pre-Nicene writers such as Ignatius, Irenaeus and Hippolytus, as well as theologians such as Athanasius and the Cappadocian Fathers. This use of florilegia heralds a new stage in doctrinal development, in that it creates a new authority for Christian theology: that of the 'Fathers'. Two works, On the Holy and Life-giving Trinity and On the Incarnation of the Lord, have survived through ascription to his opponent Cyril of Alexandria. Another surviving work by Theodoret is his Refutation of the Anathemas, his rejection of the twelve anathemas pronounced on him by Cyril of Alexandria, which has been preserved in Cyril's defence. He detects Apollinarianism in Cyril's teaching, and declines a "contracting into one" of two natures of the only begotten, as much as a separation into two sons (Epist. Cxliii). Instead of a "union according to hypostases," he would accept only one that "manifests the essential properties or modes of the natures." The man united to God was born of Mary; between God the Logos and the form of a servant a distinction must be drawn. Another surviving work is the Expositio rectae fidei. This was preserved among the writings of Justin Martyr. However, both Lebon (1930) and Sellers (1945) independently recognised it as the work of Theodoret, probably pre-dating the outbreak of the Christological controversies. Only minor fragments (cf. Epist. 16) of Theodoret's defence of Diodorus and Theodore (438-444) have been preserved. There are many lost works. Theodoret mentions having written against Arius and Eunomius, probably one work, to which were joined the three treatises against the Macedonians. There were, besides, two works against the Apollinarians, and of the Opus adversus Marcionem nothing has been preserved. God is immutable also in becoming man, the two natures are separate in Christ, and God the Logos is ever immortal and impassive. Each nature remained "pure" after the union, retaining its properties to the exclusion of all transmutation and intermixture. Of the twenty-seven orations in defence of various propositions, the first six agree in their given content with Theodoret. A few extracts from the five orations