Comparison / Contrast

Please compare and contrast [u]Dune[/u] by Frank Herbert with [u] The Teachings of Don Juan: a Yaqui Way of Knowledge[/u] by Carlos Castaneda. Both books were written during the 1960s, and tell the story of a young man (Paul / Carlos) who goes to the desert (Mexico / Arrakis), encounters a psychoactive substance (peyote / melange) and learns that he must change his way of perception in order to become greater than his current status.

Discuss why Paul succeeds whereas Carlos apparently fails. To what extent does each succeed or fail?