The mind has profound effects on physiological functioning and health. Emotional distress causes physiological stress and dysfunction, which, when chronic, eventuates in disease. In this discussion, we also address the healthy physiological effects of mind training. The concepts of self-efficacy and mastery are described. The term “mastery” is used to describe a sense that we can handle the challenges that life throws at us. Wellbeing is the good feeling that results from living with mastery. Herbert Benson and Ellen Langer of Harvard are referenced, as is Deepak Chopra, of the Chopra Center.