This talk begins with a brief survey of the history of scientific discourse on mental health, then focuses on the intellectual and professional dilemma faced by early modern physicians: either repeat Greek psychology and suppress one’s own originality or challenge the giants of Greek medicine along with their scientific and cultural weight. The lecture tells the story of how some authors in the John Martin Rare Book Room collection grappled with the authority of the past against the backdrop of an area of medicine that is of great concern in our own time.