This lecture, given to celebrate the centennial of the founding of the Henry Phipps Psychiatric Service at Johns Hopkins, addresses the career and contributions to psychiatry and neurology of Adolf Meyer, the first Phipps Professor. It reviews his achievements historically describing the bleak clinical situation of psychiatry when he began as a neuropathologist at Kankakee Hospital in Illinois in 1892, what he did to address them, the sources of help he found and exploited from leading figures in the emerging Progressive Era (1890-1917) in American life, and how he confronted and overcame resistances to his empirical, psychobiological conceptions of mental illness as he advanced. His legacy is reflected in the signal contributions of four leaders of American psychiatry (Drs. Leo Kanner, Alexander Leighton, Jerome Frank, and Paul Lemkau) who had been his residents and in those aspects of contemporary teaching and research at Hopkins that reflect his thought.