Colin Campbell (Maine) has been studying and teaching elements of magical practice for over twenty-five years with a particular emphasis on Thelema, giving lectures at both the local and national level. He is the author of several books, including A Concordance to the Holy Books of Thelema (2008), The Magic Seal of Dr. John Dee: The Sigillum Dei Aemeth (2009), and Of the Arte Goetia (2015). Visit Colin online at www.Hermetic.com/Campbell/Index.