Every once in a while you find a high impact book. Something that awakens something deep within and lasts forever. This is the one. It is a book that you can pick up time and time again and always gets something new out of it, or something deeper than you. Cheng Hsin is the best introduction for beginners to the internal practice of fighting. It is a seminal work that draws on T'ai Chi Ch'uan, Aikido, and Pa Kua Chang and was written by the first Westerner ever to win the world championship in a full-contact martial arts tournament.