James Loeb (1867–1933), one of the great patrons and philanthropists of his time, left many enduring legacies both to America, where he was born and educated, and to his ancestral Germany, where he spent the second half of his life. Organized in celebration of the sesquicentenary of his birth, the James Loeb Biennial Conferences were convened to commemorate his achievements in four areas: the Loeb Classical Library (2017), collection and connoisseurship (2019), and after pandemic postponement, psychology and medicine (2023), and music (2025). While the focus of the third conference shifted from Loeb as practitioner to Loeb as patient, the connection between his philanthropy and his personal experience remains clear and fascinating. Loeb suffered from the illness known today as severe bipolar disorder, for which he was treated by Emil Kraepelin (1856–1926), a pioneer in interdisciplinary brain and psychiatric research. Starting from the extensive records of this treatment, the volume’s contributors examine the history of mental illness from antiquity to the present in light of Loeb’s own condition, research, and contributions to medical humanism and psychiatric medicine.