THE DIATRITUS AND THERAPY IN GRAECO-ROMAN MEDICINE.

The so-called diatritus in Graeco-Roman medicine represents a therapeutic system which was designed to provide a chronological framework for the regulation of regimen in disease. Developed in the mid-first century A.D. within the Methodist school of medicine, it appears thereafter to have been a cornerstone of this school’s therapeutics, as represented in the three major Methodist treatises to have survived. In the therapeutic prescriptions recorded in the Gynaecia, Soranus (fl. late first/early second century A.D.) mentions the diatritus specifically on four occasions,2 while Caelius Aurelianus (fifth century A.D.), drawing to some extent on Soranus’ earlier work, makes constant use of it throughout his Celeres Passiones and Tardae Passiones. Galen, too, universally hostile to the diatritus, associates it almost exclusively with Methodist physicians. There is strong evidence, however, that it was employed as a therapeutic tool also outside Methodist circles. It surfaces intermittently, but without criticism, in the treatments laid down in medical treatises with no apparent links to this school, and over a considerable period of time.3 In particular, the unknown author of the treatise On Acute and Chronic Diseases, often referred to as the Anonymus Parisinus, relies on it extensively, though not systematically, in the therapeutic sections of his work.4 Yet the diatritus has for the most part received only passing reference in scholarship, largely with regard to the doctrines of Thessalus or Methodism generally, and with little or no detailed inquiry into its exact meaning or uses.5 Given its significance not only for our understanding of the development of Methodist therapeutics, but also as an example of the broader influence which Methodism may have had over ancient therapy, a more systematic study of the diatritus is warranted. In this paper I shall examine the diatritus’ origins, its precise meaning, and what it represented in its practical therapeutic contexts, both in the hands of Methodist and non-Methodist physicians. I shall also attempt to offer some suggestions as to why the chronological framework which it describes was thought to be appropriate in the treatment of disease.