This book is about education. While the subject is about teaching and learning professionalism, the authors discuss how best to educate the physicians of the future who will be responsible for much of the health and well-being of their fellow citizens. While medical education often appears to have developed in isolation from the formal world of pedagogy, medical students are adult learners and the science of cognition applies to them as it does to other learners. Through the centuries, we have come to understand a great deal about education, but there is still much that we do not know and probably will never fully comprehend. For a period of time, both general and medical education placed great emphasis on the acquisition of knowledge and skills. In our knowledge-based world, this is certainly appropriate, as one cannot function without a minimal level of knowledge. However, recent times have seen a return to an earlier belief that education represents more than facts and figures. It has been said that education is what remains after what has been learned has been forgotten. Michael Polanyi, that wonderful combination of chemist and philosopher, coined the term “tacit knowledge” to help us understand this phenomenon. He stated that “one knows things which one cannot tell.” Tacit knowledge is acquired through experiencing a broad spectrum of life's challenges.