This thesis is an investigation into the spiritual anthropology of John Cassian, who composed two monastic works, the Institutes and the Conferences. Although Cassian transmits the teachings of the Egyptian desert fathers living in the later fourth century, many polemical
mind-sets, from his Latin contemporaries to modem critics, have not been able simply to accept his delivery with a spirit of respect and support. In his texts, the doctrine of free will and grace has been judged to be Semi-Pelagian through the viewpoint of Augustinian orthodoxy. Moreover, since Salvatore Marsili's comparative study in the 1930s, it has been accepted that Cassian's ascetic theology depended heavily on the writings of Evagrius Ponticus. Thus, the authenticity of his texts has been obscured for over fifteen hundred years in the West. Consequently, they have been regarded as second-class materials in the primitive desert monastic literature. This thesis re-examines the above settled convictions, and attempts to
defend Cassian's repeated statements that he wrote what he had seen and heard in the desert. As the two assertions both relate to anthropological issues, the thesis investigates Cassian's spiritual anthropology-, human created nature, the Fall, its results, salvation, perfection, free will and grace. Chapter I uses as the context Cassian's life and the monastic setting of Gaul that
had an influence on his works. Chapter II explores a literary feature of his writings and identifies the authenticity of Cassian's texts in comparison with the desert monastic literature. Here, the thesis argues against the dominant assumption of his dependence on Evagrius'works
and reveals that Cassian was not a transmitter of the Evagrian schemata. Chapter III focuses on the instructions of created human nature in Cassian's texts and establishes that they were derived from the Alexandrian and the desert theological tradition, not that of the Evagrian
Origenist. Chapter IV deals with the Fall and its effect on human nature. In the process, the thesis verifies that Conferences XIII does not offer an alternative to the Augustinian teachings on grace, but reflects the doctrinal milieu within the Alexandrian theology, which was to be
regarded as Semi-Pelagian in the eyes of later Augustinianism. Chapter V presents soteriology in Cassian's works, in which all related texts show the Eastern synergistic tendencies regarding grace and free will as cooperating harmoniously with each other for salvation. Overall, the thesis asserts that distinctive divergences and inconsistencies among the speakers in treating
each theme serve to verify the authenticity of Cassian's Abbas.
The thesis concludes that Cassian was,indeed,the most notable transmitter of oral and lived Egyptian monastic theology to the West, as he claimed.