 For Galen, to understand a clinical case technically, ‘to diagnose’, was, among other things, to know with greater or lesser certainty the outcome for the patient, ‘to prognosticate’.Prognosis, then, is one of the essential problems and most important objectives of Galenic diagnosis.Galen was concerned with distinguishing prognosis from divination or prophecy, both to improve diagnosis technically and to enhance the physician's reputation."