In Ronald Hutton's book The Triumph of the Moon (2000) he provided in one chapter what was at that time the most fair and thorough study of Crowley's influence on the origins of modern religious witchcraft. His chapter here does not merely rehash that material, but updates it with new findings and perspectives. Unlike Introvigne, Hutton does perceive the properly religious character of Crowley's 1904 revelation and consequent activities. However, he wants to dismiss the religious dimension of Thelema on the (somewhat justifiable) basis of the magical-rather-than-religious orientation of many latter-day Thelemites. It is an understandable position for him, in defense of his slogan touting Wicca as "the only fully formed religion that England has ever given the world." (In light of the patently and confessedly religious nature of O.T.O., I would suggest a different gambit to Hutton: The revelation in Cairo to the globe-trotting adventurer Crowley, the German roots of O.T.O., and the subsequent formation of the first durable Thelemic communities outside of Britain indicates that Thelema isn't so much a product of "England" as it is an inherently intercultural, cosmopolitan synthesis.) As in The Triumph of the Moon, Hutton is here focused on English witchcraft, especially as formulated by Gerald Gardner. He consequently gives no attention to the witchcrafts of American Jack Parsons and Australian Rosaleen Norton, both strongly influenced by Crowley themselves, and not via Gardner's work.
The case of Norton is taken up in a study by Keith Richmond, who does her full justice. Adding nothing substantial to the reader's knowledge of Crowley himself, Richmond instead illuminates Norton's regard for and understanding of Crowley. She seems to have been friendlier to Crowley's work in private than in public, which is understandable, in that she had no need to borrow notoriety!
Hugh Urban's chapter treats Crowley's possible influence on L. Ron Hubbard and the Church of Scientology. Urban does some contextual violence to various Crowley quotes from Magick in Theory and Practice, but his readings may be consistent with the way Hubbard approached the material, so for immediate purposes there's not much point in arguing about them. The chapter's thesis is the conclusion that any dispassionate observer should reach: Hubbard was influenced by Crowley, but Scientology incorporates so many other elements -- some others of which have come to predominate while the ones rooted in magick have faded -- that it would be false to simply view it as some sort of crypto-Thelema.
The final chapter, contributed by Asbjorn Dyrendal, is an assessment of Crowley's influence on two of the seminal organizers of contemporary Satanism: Anton LaVey and Michael Aquino, of the Church of Satan and Temple of Set respectively. Although there is a little confusion of the distinct notions of "black magic" and the "Black Brotherhood" in Crowley's work, this examination is conducted with great care and accuracy on the whole, pointing out both debts to Crowley and explicit rejections by Satanists of some of his teachings. It is interesting to contrast the Satanists' criticisms of Crowley with Urban's appraisals of him, since they come to such different conclusions. (While I differ with their ultimate valuations, I think the Satanists are more accurate here.) Although Dyrendal touches briefly on LaVey's successor Peter Gilmore, he keeps the discussion very focused on the two Satanist founder figures, and it would have been interesting to bring in some of Don Webb's outspoken opinions on Crowley, for example (he wrote a short monograph called Aleister Crowley: The Fire and the Force), thus demonstrating Crowley's direct effects on the enduring Satanist milieu.
With a few minor exceptions, the level of scholarship in this volume is considerable. More than that, the papers tend to be lively and challenging reading. As Wouter Hanegraaff points out in his foreword, the caricature of Crowley as a quasi-medieval Doctor Faustus conceals a figure who is quintessentially modern, and to give the Beast his third dimension places him in the same space that the reader inhabits.