Pain is very difficult to define. The Introduction explains that a true understanding of physical and emotional pain must take into account biological, psychological, and social factors. Pain has become one of the most challenging medical mysteries of modern times, in terms of how it works, how to treat it, and what it means, and there has been much research into pain phenomena. But none of this will make sense without first introducing the languages, cultures, and historical variabilities of pain. This VSI does not just dwell on first-hand pain, it also considers how we conceive, understand, and experience the pain of others.