While at Harvard and the Brigham, he and his colleagues began to systematically study how to diagnose and treat pulmonary hypertension and pulmonary embolism (PE) and published seminal works on pulmonary angiography to diagnose PE, urokinase to treat PE, the identification and classification of three clinical syndromes associated with PE, and how best to treat pulmonary hypertension due to mitral valve disease. While at the University of Massachusetts Medical School and Medical Center, he and his colleagues were among the first to question the safety of the pulmonary artery flotation catheter. By partnering with Jack Hirsh, Jim and Jack conceived of, developed, and published the first American College of Chest Physicians Antithrombotic Clinical Practice Guidelines, the prototype of trustworthy guidelines and among the very first evidence-based clinical practice guidelines. The current practice of treating atrial fibrillation with anticoagulants began with these guidelines. This practice has prevented thousands of strokes. Moreover, Jim helped nurture and supported Jon Kabat-Zinn’s work, which led to the creation of the Stress Reduction Clinic and the Center for Mindfulness in Medicine, Health Care, and Society at the University of Massachusetts Medical School, and the discipline of mindfulness-based stress reduction. While at the University of Arizona College of Medicine, Jim was a leader among the early group of deans of major medical schools who recognized the importance of integrative medicine and supported the need for an organization to promote integrative medicine in the academic environment. With the active participation of Andrew Weil, this led to the creation of the Academic Consortium for Integrative Medicine and Health and the Arizona Center for Integrative Medicine. Jim was also instrumental in the establishment of the University of Arizona College of Public Health. As Dean Emeritus and Executive Director of the Weil Foundation, Jim continues to be an advocate for public health, social justice, and health-care reform and has yet to put down his pen.