Diagnosis is arguably the most important job of a physician. But what does it actually mean to make a diagnosis? In this episode, we’ll explore this question by tracking the development of the “classical” model of diagnosis and pathological anatomy and discussing three cases over three hundred years. Along the way, we’ll ponder the concept of the lesion, iatromechanistic theories of the human machine, the birth of the International Classification of Diseases, and the rise and decline of the autopsy. You can sign up for the iMED Digital Education conference at cmeregistration.hms.harvard.edu/digitaleducation.   Sources: Hooper R, The Physician’s Vade-Mecum: Containing the Symptoms, Causes, Diagnosis, Prognosis and Treatment of Diseases. 1812.  Holdman L et al, The Value of the Autopsy in Three Medical Eras. N Engl J Med 1983; 308:1000-1005. Cabot RC et al. CASE RECORDS OF THE MASSACHUSETTS GENERAL HOSPITALANTE-MORTEM AND POST-MORTEM RECORDS AS USED IN WEEKLY CLINICO-PATHOLOGICAL EXERCISES. Case 9431. Boston Med Surg J 1923; 189:595-599. Shojania KG and Burton EC, The Vanishing Nonforensic Autopsy. N Engl J Med 2008; 358:873-875 Morgagni GB. The seats and causes of diseases investigated by anatomy in five books, containing a great variety of dissections, with remarks. To which are added ... copious indexes. 1769. Retrieved online: https://openlibrary.org/works/OL15821973W/The_seats_and_causes_of_diseases_investigated_by_anatomy Castiglioni A, GB Morgagni and the Anatomico-pathological Conception of the Clinical. Proceedings of the Royal Society of Medicine, November 7, 1934. Thiene G, Padua University: The role it has played in the History of Medicine and Cardiology and its position today. European Heart Journal, Volume 30, Issue 6, March 2009, Pages 629–635. Zampieri F et al, Origin and development of modern medicine at the University of Padua and the role of the “Serenissima” Republic of Venice. Glob Cardiol Sci Pract. 2013; 2013(2): 149–162. Conner, Annastasia (2017) "Galen’s Analogy: Animal Experimentation and Anatomy in the Second Century C.E.," Anthós: Vol. 8: Iss. 1, Article 9.  Zampieri F et al. The clinico-pathological conference, based upon Giovanni Battista Morgagni's legacy, remains of fundamental importance even in the era of the vanishing autopsy. Virchows Arch. 2015 Sep;467(3):249-54. Ghosh SK, Giovanni Battista Morgagni (1682-1771): father of pathologic anatomy and pioneer of modern medicine. Anat Sci Int. 2017 Jun;92(3):305-312.  O’Neal JC, Auenbrugger, Corvisart, and the Perception of Disease. Eighteenth-Century Studies Vol. 31, No. 4, The Mind/Body Problem (Summer, 1998), pp. 473-489 Brown TM, THE COLLEGE OF PHYSICIANS AND THE ACCEPTANCE OF IATROMECHANISM IN ENGLAND,