The physician must be learned in diagnosing, careful and accurate in prescribing, circumspect and cautious in answering questions, ambiguous in making prognosis, just in making promises; and he should not promise health because in doing so he would assume a divine function and insult God.

In: Henry E. Sigerist (trans.), Bedside Manners in the Middle Ages: The Treatise De Cautelis Medicorum Attributed to Arnald of Villanova