Hmm ... maybe I shouldn't have said that, since I wasn't interested in those things before I read those books either! (Nor have I been since.)
Anyway, those two of Powers's books are superbly written and intriguing, blending history with unique ideas about the supernatural -- even though they might be about the tarot, poker, spies and/or djinn.
I find the Tarot fascinating as a system of symbols (in fact I find the use of symbolism in general by humans a fascinating field of study).
Of course, the deck of cards was originally invented merely to play card games with, around the 15th century, mainly starting in Italy with a suspected Egyptian influence, but later spreading to the rest of Europe.
It was only a few centuries later, that the deck became associated with esoteric and divinitory uses, most probably because the symbolism depicted in the deck appears to be so apt to the way that humans see the world in a subconscious, symbolic sense.
The deck tends to describe universal elements such as "Ruin" , "chaos", "death", "rebirth", "order" ,"relationships", "love", "justice", "temptation", the peasantry, the merchant class, nobility, earth, fire and water, father, mother, sibling, and so on.
This, of course, also make the elements described in the deck and their respective "avatars" or "symbols" a very interesting source for fantasy fiction, and for exploration of the human subconscious by means of fantasy and symbolism.
On topic: I've just started with Kostova's Historian. I'm liking it so far, but too early to tell why so many people seem to dislike the book.
