The Book of Thoth: A Short Essay on the Tarot of the Egyptians, Being the Equinox Volume III No. V
by Aleister Crowley
1974

Based on medieval symbolism and ancient Kabbalistic tradition.

EXCERPT:

The Tarot is a pack of seventy-eight cards. There are four suits, as in modern playing cards, which are derived from it. But the Court cards number four instead of three. In addition, there are twenty-two cards called "Trumps", each of which is a symbolic picture with a title itself. At first sight one would suppose this arrangement to be arbitrary, but it is not. It is necessitated, as will appear later, by the structure of the universe, and in particular of the Solar System, as symbolized by the Holy Qabalah. This will be explained in due course...