One thing I'm noticing in these older books is a lack of, for want of a better term, "White Wolf hubris." Maybe I'm still sore from the gross stuff in Guide to the Sabbat, but I remember late-90s WW as being the company that would say anything for shock value. In books like Clanbook: Giovanni and as recently as Manual of Exalted Power: Infernals, it almost feels like they were not only confident they could get away with it, but that they bought into the idea that it was their duty, as the mature rpg company to be as gross as possible.
Yet, as of The Book of Madness, they still seem new and vulnerable enough that they don't always go for the worst thing imaginable. Sometimes, they even show discretion. In a book that is full of murderers, demons, and dark sorcerers, there's really only one paragraph where I felt like I wanted to bury my head in revulsion . . . and it described a real guy.
Don't get me wrong, I learned more about Gilles de Rais than I ever wanted to know (and seriously, if you google that name - beware), but surprisingly, the book was as relatively tasteful as could reasonably be expected, given the subject matter. You do have to ask yourself whether it's appropriate or wise to make a real-life child-murderer into a villain in your fantasy roleplaying game, but I'm honestly not sure whether using a 500-year-old crime in this way is worse than imagining such lurid atrocities anew.
And I'm sorry I'm being so vague about this. I know it can be pretty stressful, but trust me, whatever you're imagining I'm not saying, the reality is worse. Although, the accusations against de Rais are so over-the-top disgusting that it makes me wonder if perhaps history has slandered the man. The one thing that makes me suspect that there are true crimes at work here is that the court record mentions the specific name of one of the victims - a common boy named Jeudon - which isn't something that usually happens in contemporary satanic panic cases. It seems probable to me that de Rais was responsible for his disappearance under mysterious circumstances, even if all of the Satan-worshipping accusations were pure embellishment.
And no, I don't know what makes me feel qualified to make those sorts of judgements after reading a twenty-five-year-old rpg book and a single wikipedia article. It's just a hunch.
Anyway, back to the subject at hand. Aside from that one low point, The Book of Madness is mostly pretty vague about the atrocities of its "mad" factions. There's a group that believes they can reset consensual reality by murdering five billion people, but canonically they aren't nearly organized enough to bring it about, and thus there's no concrete details about the Bai Dai's crimes against humanity.
It's almost shocking how PG-13 the section on demons is.I get the feeling that they are almost obligatory. Demons are something you expect to see in a modern horror setting, so demons are what we get. The book doesn't do anything particularly imaginative with them, and while we hear that they love to torture the souls they buy from people, it's described only in the most general of terms.
The most important chapter in the book, and probably the only one with any real legs, was the one about Paradox. It's kind of a landmark. The stuff from the core about the Technocracy being the reality cops gets dialed way back. Now they merely strengthened the Gauntlet (barrier between material and spirit world) instead of creating it. And Paradox itself is cast for the first time as a neutral cosmic force and not something unnatural that the Traditions are ultimately going to be able to defeat.
To quote the chapter, "the rock will not move or break apart unless it believes itself to have been acted upon by a sufficient physical force." The idea that Mage is a game about exploring the nuances and consequences of consensual reality is starting to come into its own. I especially love the way it dovetails with the animistic of the World of Darkness' spirit realm. The beliefs of apparently "inanimate" objects and "nonsapient" animals factoring in to the consensus is an easy answer for why the world doesn't always conveniently match up to the most powerful human belief systems.
Speaking of which, there's a taxonomy of spiritual beings here and Gaia is explicitly identified with the Abrahamic god. It's a throwaway line, but at least until a later book comes around to fix it, every monotheistic religion in the World of Darkness is canonically established to worship different masks of the same creator spirit.
Maybe there was a bit of White Wolf hubris after all.
Ukss Contribution - The Dust Witch. A paradox spirit that shows up and gets dust all over everything. Especially unlucky people might be cursed to turn every non-living thing they touch into dust. Aside from triggering allergies, she's mostly harmless. Just a weird, obsessive creep who shows up and scolds you for getting sloppy with your magic.