ABSTRACT
This chapter presents agreed-upon descriptions of the nature of the fact/event of pain. In the last half century, we have come to understand a great deal about pain as a physiological fact/event. Thus, the philosopher Valerie Gray Hardcastle argues that the brain states that give rise to the experience of pain can better be described in neuro-physiological rather than psychological terms. But whether or not the Melzack/Wall or the Hardcastle explanation more fully accounts for the physiology of pain, it is clear that pain messages can change within the peripheral nerves, the spinal cord, and the brain. Moreover, the general physiological account of pain set forth in this chapter, particularly its three modalities associated with different fibers and inflammation, are most concerned with an episode of acute pain.
