Philosophers have long recognized that the unique values of the individual physician effect medical-ethical decision-making. While not taking issue with this basic assumption, this article critically examines one discussion of how different philosophies (existential, utilitarian, and value realist) can influence a neurosurgeon's decision to operate upon a person having a malignant brain tumor. It also delineates and discusses a fund of ‘medical wisdom’ commonly available to any neurosurgeon and easily obtainable by both researcher and patient. The article suggests that those in the humanities interested in studying the ethical decision-making process in a medical subspecialty become familiar with this fund of knowledge. It can provide a base for evaluating when and how individual medical decisions vary. In this specific instance, the medical knowledge base was used to direct attention to when and how ethical issues are identified and resolved within the staff clinical neurosurgical setting. An informal survey among resident and staff neurosurgeons supported the conclusion that philosophical analyses of medical-ethical decision-making are appreciated when case examples are carefully and accurately documented, when medical terminology is used correctly and when recognition of the practical limits placed on medical decision-making is given.