We began this book with the historical precursors of current opponent process theory. We presented an epistemic foundation for OPT beginning with adversarial notions in philosophy and religion and progressing to greater scientific rigor, particularly the opponent visual afterimages and data from neurophysiological research. Within these prevailing influences emerged the contributions of Soloman and Corbit extending opponent process conceptions to human holistic behavior. And we cannot neglect the inspiration of the documented emotional contrasts evinced by paratroopers before and after parachute jumps. All of this eventually produced refutable hypotheses and a testable model of opponent processes and acquired motivation, constituting the data basis for this book.