 In the foreword, Castaneda gives "full credit" for the approval of his dissertation to Meighan).He offers a new thesis on a mind-state he calls "total freedom" and claims that he used the teachings of his Yaqui shaman as "springboards into new horizons of cognition".In addition, it contains a foreword by anthropologist Walter Goldschmidt, who was a professor of anthropology at UCLA during the time the books were written, and an introduction by the author.