I've got some serious issues with Raven Grimassi's methodology. He has a very bad habit of assuming that any evidence for witchcraft prior to Gerald Gardner's publication of Witchcraft Today automatically demonstrates that Wicca is older than Gardner. Raven never quite assimilated the concept that "Wicca" and "witchcraft" are not interchangeable terms. Unfortunately, the evidence does not support Raven's assumption. Wicca is a modern religion based in part on Margaret Murray's thesis about the nature of European witchcraft. Textual analysis of the earliest Wiccan material, written in Gerald Gardner's own hand, has pretty conclusively demonstrated that Wicca was a brilliant synthesis of material taken from roughly a hundred disparate primary sources, all of which were available to Gerald Gardner either from his personal library or in the collection of the British Library. While I do recommend that persons interested in the early history of Wicca read Philip Heselton's books Wiccan Roots and Gerald Gardner and the Cauldron of Inspiration, I always caution them that Heselton's interpretations of some of his findings are questionable. Heselton has a bad habit of stating in Chapter 2 that the evidence suggests that "A" may be true, and then starting his discussion in Chapter 3 as if the truth of "A" were already demonstrated beyond question. In my view he also misinterprets the writings of both Dorothy St Quentin-Fordham and of Katherine Oldmeadow, imputing pagan themes to their writing when what is actually present is the flowery formal writing style, littered with allusions to Greek and Roman deities, typical of members of Britain's upper classes in the Edwardian period who had been the beneficiaries of a classic British public-school education. It is probably appropriate too to mention Ronald Hutton's The Triumph of the Moon while we are on this subject. While a good many people on the Web seem to feel compelled to throw brickbats at Hutton over the faults they perceive in the material in the book, or over perceived faults in Hutton's approach to that material, TotM is still the only historical examination of the origins of Wicca which approaches the subject with anything resembling traditional academic rigor. It's a dry read in many places, but an essential one for anyone with a serious interest in the subject.