Three historical roots of consulting psychology that have influenced its development are "the wise old man" archetype identified by Jung, charlatanism, and functionalism. This article traces these concepts from antiquity to their residual presence in the consulting practices of today and explores them by using analogies and practical work examples. It also reviews the evolution of formalized organizations of consulting psychology. Multiple sources are cited from literature, research, and the experiences of consultants in the field. The author discusses the inherent dangers of consultants drinking their own snake oil, of misperceiving style as substance, and of succumbing to the standards of the marketplace rather than adhering to those of the profession.