The EXODUS of public health. What history can tell us about the future.

We trace the shifting definitions of the American public health profession's mission as a social reform and science-based endeavor. Its authority coalesced in the late nineteenth and early twentieth centuries as public health identified itself with housing, sanitation, and labor reform efforts. The field ceded that authority to medicine and other professions as it jettisoned its social mission in favor of a science-based identity. Understanding the potential for achieving progressive social change as it moves forward will require careful consideration of the industrial, structural, and intellectual forces that oppose radical reform and the identification of constituencies with which professionals can align to bring science to bear on the most pressing challenges of the day.