Steven C. Hayes, PhD, is Nevada Foundation Professor and director of clinical training at the department of psychology at the University of Nevada. An author of 38 books and over 540 scientific articles, his career has focused on analysis of the nature of human language and cognition, and its application to the understanding and alleviation of human suffering and promotion of human prosperity. Among other associations, Hayes has been president of the Association for Behavioral and Cognitive Therapy, and the Association for Contextual Behavioral Science. His work has received several awards, in...