Divination, prognosis and prophylaxis: the Hippocratic work 'on dreams' (De victu 4) and its Near Eastern background.

Building on the results of recent scholarship concerning the coherence of the Hippocratic work De victu ('On Regimen'), this chapter discusses the close connections between Book 4, which deals with the use of dreams for medical prognosis and especially prophylaxis (which the author claims to be his own innovation), with the rest of the work. It analyses the author's position on dreams and their interpretation and his stance against professional dream interpreters. It distinguishes five categories in the author's discussion: 1. the signs, i.e. the dream images themselves; 2. the significance of the dreams; 3. explanations of the relationship between sign and significance; 4. prophylactic (dietetic) measures to prevent disease; 5. instructions as to the gods one should pray to in order to prevent disease. It explores the rationale underlying these categories and lists a number of parallels with Babylonian dream literature. It concludes that although there are important differences with respect to the use of dreams in Babylonian medicine, it is not implausible that the author of De victu 4 has borrowed some of his material from Near Eastern dream books. At the same time, the author of De victu 4 distances himself from oneiromantic practices that are very similar to what we find in Babylonia; and his elaborate interpretative system linking specific dreams to specific bodily disorders goes far beyond anything found in Near Eastern sources (but also beyond anything else in the Corpus Hippocraticum). He does accept the existence of dreams sent by the gods and of prayer to the gods in combination with dietetic prophylaxis; but his elaborate use of dietetics for preventive purposes marks an important innovation when compared to Babylonian medicine. The author is not concerned with incubation.