In recent years, there has been a large and rapid increase in the number of practicing neurologists in the United States. This information alone, however, says little about whether this change has had beneficial or deleterious effects on the quality and cost-effectiveness of neurologic care for the majority of patients. Before one can determine the optimum number of specialists in a population to be served, one must first specify what role such physicians will fill, along with other groups of generalists and specialists, in the provision of medical care. Hence the general question: What is the scope of neurologic practice and care? In attempting to answer this question, I would suggest that one needs to separate dogma from evidence. What we would like practicing neurologists to do may be different from what is actually done. Even a physician's self-perception of professional activity may differ in important ways from measured data.