Amazon.com description: Product Description: All attempts to test people's ESP abilities overlook the fact that ESP is an undeveloped function, so we have to learn how to use it to begin with, not just see how much ESP we can show.Psychologist Charles T. Tart applied basic principles of learning to this task to show how training under conditions of immediate feedback could enhance ESP ability. This highly readable book, originally published by the University of Chicago Press, is the theory and a comprehensive study suggesting the principles can work.