David L. Rosenhan (1929-2012) was a distinguished psychologist and professor emeritus at Stanford University. He held a range of academic qualifications, including a doctorate in psychology from Columbia University and a range of degrees in law and mathematics, and he was also a leading figure in psychiatric ethics. These academic achievements paved the way for a career deeply concerned with the intersection of law, psychology, and ethics.

Rosenhan is not merely the author of “On Being Sane in Insane Places” but also the architect of and a participant in the experiment that forms the essay’s backbone. He was likewise deeply engaged in the analysis and interpretation of the data, drawing conclusions that would have a lasting impact on the field of mental health. Rosenhan’s experiment, where mentally healthy individuals were admitted to psychiatric hospitals, revealed the ease with which “sanity” could be mistaken for “insanity,” pointing to the potential Unreliability of Psychiatric Diagnoses. His essay became a seminal text in the anti-psychiatry movement, influencing the debate on mental health care and the rights of patients; it impacted not only psychiatric practice but also the public perception of mental health and the treatment of marginalized individuals in society. His essay continues to be a touchstone for discussions about the nature of mental illness and the ethics of diagnosis and treatment.