The RZA has a new book out called "The Tao of Wu," and I'm looking forward to reading it. I read "The Wu-Tang Manual" a few years ago and still have it on my shelf for reference. Droppin' Knowledge, the 5% Nation's method of passing on wisdom, is inherent in hip hop. Breaking down words, for instance, is a means of getting to the root of knowledge in common names for things like Libraries (ie. lies buried), or changing the use of Romance lettering (ie. Z's instead of S's). Mathematics is a fundamental principle, apparently. Therefore, the Wu/Hip-Hop/5% philosophy is a method of wisdom that uses evidence with strong universality (ie. mathematics) as a means of self-mastery.
When I read the Manual I wondered if the RZA would be going a series of books. I'm happy to see that the answer is affirmative!