I think that The Citadel depicts an organization of medical practice in the United Kingdom as predicated upon external reality, as opposed to it being determined on the basis of sound medical judgment. Cronin offers a vision of medical practice where there are external forces which weigh upon medical professions. Judgments, diagnoses, and actions are not made without considering these external realities. The organizational structure of medical practice is shown to be one where doctors are subject to an external force. Only when they make a conscious choice to escape this reality does Cronin believe that doctors can be free to practice a purer form of medicine.
The Citadel depicts the external reality that defines the organization of medical practice in the United Kingdom in distinct manner weighs upon the medical community. Andrew sees this in Aberalaw. The organization of medical practice is predicated upon public approval. Doctors are not free to make medical diagnoses without the consent of the community. When workers like Chenkin demand notes for leave of work and threaten Andrew with being black listed and brought in front of inquiry committees as a response, it is clear that the organization of medical practice is based upon external reality. Andrew is unable to act in accordance with what he feels is right because of the need to appease this external force. Even when he does act in good conscience, he must pay a strict price for it. In this setting, the organization of medical practice is contingent on an external reality, the approval of the public.
When Andrew moves to London, another external reality defines the organization of medical practice in the United Kingdom. Andrew comes across the material element as playing a critical role in the organization of the medical community. Andrew realizes that doctors, himself included, use patients as a means to an end. The drive to acquire greater material wealth is what organizes medical practice. Doctors consult one another in order to increase their billings and end up convincing patients that expensive procedures are needed when none of the sort is really needed. In London, Andrew recognizes how money and wealth drive the organization of medical practice.