Greek Medicine from Hippocrates to Galen: Studies in Ancient Medicine Edited by John Scarborough Philip J. van der Eijk Ann Ellis Hanson Joseph Ziegler states,

“That a doctor from the fifth century needed to combine the art of persuasion and the art of healing is better understood if we account for the situation of a doctor in this period. In the absence of any regulation of the medical profession, the doctor had to compete constantly with his rivals both for his medical competence and his art of persuasion, whether this was before an audience limited to the entourage of patients during home visits, or before the larger public in a doctor’s surgery or, finally, before the peoples’ assembly. “

“The usefulness of the art of persuasion in a medical career is attested indirectly by a passage of Plato’s Gorgias: “Often,” Gorgias says to Socrates (456 b), “when I have accompanied my brother or some other doctor to see one of his patients who refused to drink a medicine or trust the doctor to operate on him with a knife or fire, whilst the doctor was not able to persuade him, I have succeeded in persuading him solely by the use of rhetoric.” "