"The art is long and the life short": the letters of Wilder Penfield and Harvey Cushing.

Wilder Penfield and Harvey Cushing created legacies to neurosurgery, both in terms of those they trained and in their philosophical approach to the field. Their biographies provide only brief comments on their relationship without any thorough examination of their personal correspondence. In this article the Penfield-Cushing relationship is examined through an analysis of their unpublished personal letters. The Penfield-Cushing correspondence is a treasure for neurosurgery: it provides remarkable insight into the embryonic period of the discipline and into the relationship of two of the most influential figures in modern neurosurgery.