Martial books

To simply practice forms and techniques, the physical aspects of martial art is to be but a mere brute. To solely read martial books without doing any physical training is to be but a weak scholar. Thus, for a real martial artist, he or she must do both.
In terms of martial arts, it is better to think of it as being analogous to religion. Every martial discipline is a different religion; the martial schools are the temples or church, and the Masters are the foremost authority within such an institution. However, despite the Masters being the foremost authority in a martial school, they are by no means the sole authority of a martial style because they are but one Master and they can only offer their own perspective pertaining to the discipline. There are hundreds and thousands of other Masters of the same discipline; everyone is able to perceive an aspect of the martial style but no one is able to comprehend it in its entirety. Thus, in order for a martial artist to perceive more and gain a better understanding of their Art, they must become a voracious reader. They must read as many martial books as possible.
Once a martial artist has gained a proficient understanding of their respective martial style, they should also read martial books of other martial disciplines. The reason being, if you'll excuse me for being polytheistic, focusing on a particular martial style is analogous to worshipping only one deity; one must be exposed and understand the nature of other deities in order to gain a greater understanding of religion.
Thinking from a larger scope perspective, initially one should treat their martial discipline as their personal religion but as they progress as a martial artist, they must step out of that limited mentality and regard martial art in general as a single religion.
The martial books, even if they be diverse, different on the surface for belonging to different martial disciplines, they are all different routes towards the same eventual goal: the understanding of martial art.