Applbaum, Arthur Isak. "The Idea of Legitimate Authority in the Practice of Medicine." AMA Journal of Ethics 19.2 (February 2017): 207-213.
Legitimate authority is the normative power to govern, where a normative power is the ability to change the normative situation of others. Correlatively, when one has the normative power to govern others, these others face a normative liability to be governed. So understood, physicians do not have legitimate authority over their patients, and patients do not have legitimate authority over their physicians. An authority is legitimate only when it is a free group agent constituted by its free members. On this conception, associations of physicians sometimes have legitimate authority over individual physicians, and physicians sometimes count as members subject to the legitimate authority of these associations. This might be so even when they have not consented to membership.