First of all – I agree! You absolutely SHOULD use any magic you want to use in your campaign. You should use anything you like, that is the first rule of TTRPG to me.
Second, John Dee is certainly an interesting character (did you see the news about his Aztec mirror?) although also in some ways a tragic one. I would also say that Golden Dawn / OTO etc. have been very sloppy with his version of the tradition. I would also say that as interesting a figure as Dee is there are quite a few more interesting characters in Continental Europe during the same period, particularly in Italy.
If I was going to pick a single figure to center my portrayal of Renaissance Magic though it would probably Cornelius Agrippa, as well as various others around and linked to him directly or indirectly (including Dr. Faustus).
I don’t think I left a big hole where black magic or demonology would be, there are demons in the book and some pretty nasty black magic spells. I just included a lot of other things around it. All the ‘gray area’ magic which seemed to be so common – I find that pretty interesting. If anything, I believe the more ostensibly ‘benign’ traditions such as the Cunning Man / Cunning Woman phenomenon doesn’t get it’s due in most RPGs or genre fiction. I think the whole gray area, not quite purely good but not quite truly evil either, is a big part of the whole medieval mentality, if you catch my meaning.
Regarding what kind of books were available in medieval bookshelves and so on, I think there is ongoing study on that subject! I know that of the six anonymous 15th Century necromantic grimoires that have been discovered in Europe (that I’m aware of) in the last 50 years or so only two have been partially published and so far as I know none of them have been released in a full English translation. Apparently there is a Russian translation of the CLM 849 now (since 2019) but I don’t have the skill to read Russian sadly.
This book is about this exact subject. It seeks to determine what kind of grimoires were on people’s bookshelves (and in libraries) and if, and to what extent goetic magic was being taught at Charles University in Prague and Jagiellonian University in Krakow. It’s a very interesting exploration (and well worth a read IMO) but he doesn’t have a definitive answer to that question.
He does however note for example that while the first three volumes of the Picatrix show up in many library catalogues in the 15th Century, the fourth volume is somewhat rarer (perhaps kept in a back room). And this is in the far more tolerant medieval period, compared to the later times when such things could get you burned. Overall though I think the jury is still out on this question. I would love to learn more.
I have Klassen’s 2015 book though I don’t have his more recent book on Elizabethan magic, as well as several works by Richard Kieckhefer, Francis Yates, and most of the main primary sources, including Agrippa, Picatrix, Book of Honorius etc..
I agree there is not such a huge difference between 15th and 16th Century magic but I think there is certainly a change by the time you get to the 17th and 18th Centuries. Wouldn’t you agree? 16th Century is a time of transition and there are many threads of esoteric philosophy woven through it. You have the mnemonic traditions of Raymond Lull being revived by Bruno, and attempt to consolidate alchemy, medicine and image magic by Paracelsus, various traditions of christian kaballah such as pursued by people like Ficino and so many of the neo-Platonists, and the gradually the rise of the Ars Notoria which would become so prevalent in later periods.
I am not really an expert on this subject, I have learned a little through the fencing manuals and reading about their context for years, and I kind of took a crash course on it all when I was writing Superno. But I get the impression there is still a lot to learn particularly from the medieval traditions (which I would say continue for a while into the 16th Century).
Superno was an attempt to show the width and breadth of the phenomenon of magic in the medieval period. I believe I did include a fairly reasonable sampling (plus some made up stuff for the amusement of the gamers). My critique of the 17th-18th Century and later traditions which focus so much on the Ars Goetia is not necessarily that it’s so naughty, as that it less interesting to me from a gaming perspective (or say, genre fiction). You certainly have some pretty chilling rituals in the CLM 849 and the Rawlings Necromantic Manuscript and several of the spells within do explicitly invoke demonic spirits, but they are complex and interesting rituals to me. It’s not purely about just summoning the right demon, abjuring them and then asking for favors.
That said, I think there is room to do a few more books in the Superno tradition, maybe one day I’ll dive into that direction, or maybe a bit more in the middle eastern direction. Did you ever see our little joke about the dreaded Jinn AL Barquan?