This text shows how the perennial appeal of Hippocratic practice helped establish the relationship between scientific medicine and monotheistic religion. After the first century Hippocratic medicine had to compete with religious healers from Asclepius to Jesus, and yet the ascendance of religions such as Christianity did not diminish the stature of Hippocratic science. Owsei Temkin is a member of the America's National Academy of Sciences and was recipient of the Prize for Distinguished Scholarship in the Humanities from the American Council of Learned Societies. Among his previous books are "The Falling Sickness: A History of Epilepsy from the Greeks to the Beginning of Modern Neurology" and "The Double Face of Janus and Other Essays in the History of Medicine".