The present collection by Professor Garc -a-Ballester deals with medicine and science (i.e. natural philosophy) in the Spanish kingdoms of Castile and Aragon between the 13th and the 17th centuries. It includes a new English version of a major study first published in Spanish. While sharing much, including Galenism (which is the subject of a further collection) as a dominant medical doctrine, with other parts of medieval and Renaissance Europe, Spain was unique in having a medical marketplace uniting Christian, Jewish, Muslim and converso practitioners. The complex processes of cultural interchange that resulted form the main theme in this book. Together, these studies have thrown new light on problems of theory and practice, perceptions of health and disease, and the doctor-patient relationship, as well as on the social and legal settings where the healers (physicians, surgeons, barbers, and apothecaries) of these different religious communities were at work.