Everything you need to understand or teach The Witches of Karres by James H. Schmitz.
The Witches of Karres combines an unconventional young man's search for his niche in life with an elaborate narrative of political and commercial intrigue on a grand scale. In this book, set in the distant future, humanity has colonized much of the galaxy, and has diversified into a variety of types, some with very special powers. It is a chance encounter with three young citizens of the planet Karres...