When Jews still lived in a closed Jewish quarter and had to seek the protection of the holders of political power, every encounter between Jews and Gentiles had its well-defined aim. According to Jacob Katz, the “transaction of business, the teaching of Jew by Gentile or vice versa, the treatment by doctors of a patient from the other community, are the recurrent patterns of social encounters between Jews and Gentiles.” Although historians have dealt extensively with the medieval Jewish moneylender and the early modern court Jew, they have seldom taken into account the relationship between Jews and non-Jews that was not governed primarily by the immediate purpose of commerce. The few (mostly Jewish) scholars who have taken an interest in the history of Jewish medicine write about great Jewish physicians, their medical works, and their achievements. But historians have left out the most important aspect, namely, that the medical practice of the rank-and-file Jewish physician brought him into close contact with Gentiles of varying social status. The picture of the Jew waiting at home for the Gentile to bring him his urine is certainly a realistic one. But the details of this picture are blurred, because of the lack of sources.