This chapter reviews historical and modern perspectives on the positive emotion of compassion. From the time of Aristotle, compassion has been defined as an emotion experienced when individuals witness another person suffering through serious troubles, which are not self-inflicted and that we can picture ourselves experiencing. Compassion at its core is, therefore, a process of connecting by identifying with another person. The identification with others generated from compassion can then provide the motivation to do something to relieve the suffering of others. Compassion is, therefore, an emotion that is vital to the practice of medicine, psychology, and other helping professions. The chapter concludes by proposing that one future topic for the field of positive psychology will be to develop interventions and educational programs that instill compassion in helping professionals.