This book searches for the deep and hidden reasons of typographical choices.
The mixing of type, the size and layout of a page, the matching between type and text are explained in terms of conceptual reasons which go far beyond the more down-to-earth perceptive approach typographers usually take.
For instance, the size of pages is linked to the intervals of music (octave, fourth, and so on) and to the Fibonacci series and, of course, to the golden section.
It is, therefore, a pythagoric vision of typography.
I think practical people will dislike it and consider it unnecessarily affected and, speaking for myself, I considered it too far fetched.
But because the author is very clear and writes well, you are never left in doubt about what he means, and, therefore, you can make up your mind as to accept or rejects his views.
Even if I found the arguments artificial, the fact remains that it is plenty of good advice on all the finer points of typography and, more than that, it is one of the really beautifull recent books I have read.
So, if you choose to judge the author by the results he achieves and not for the reasons he claims are the cause of that achievement, you can only respect and admire the author and his principles.
Certainly a must.