Sine qua non: the formulation of a theory of neurosurgery.

Fundamental postulates underlying the fabric of biomedicine are rarely discussed, much less seen in print. Scientific surgery and its subspecialties are relatively new fields, and their philosophical basis has received little attention since Halsted's day. During the last quarter century, we have "reinvented" neurosurgery, and a concatenation of forces is escalating that is further accelerated by technological change. Social, economic, political, and scientific climates concurrently exert unusually stressful influences on all practitioners, irrespective of the individual setting. This provides a reason to reexamine what neurosurgeons do and why, and to attempt to define the guidelines of theoretical basis for the specialty of neurosurgery and its procedures. This article examines the accomplishments of past generations in an effort to establish surgical substrata and proceeds to attempt to readdress elements of a theoretical basis of our current practice.