Dr. Mark Siegler is a founding figure in the field of clinical medical ethics. This brief chapter discusses how he personally revitalized the field of medical ethics, which was not serving patients or physicians sufficiently when he began his work in the 1970s. Dr. Siegler’s compassion, generosity, devotion to patient welfare, and attention to the doctor-patient relationship led to the founding of both the MacLean Center for Clinical Medical Ethics and the Bucksbaum Institute. Through the efforts of Dr. Siegler and these organizations, hundreds of physicians and health care professionals have been trained in the field of clinical medical ethics and the principle of caring has been embedded in the training and preparation of future physicians and clinicians.