The Tao Te Ching and Ping-fa (the incorrectly labelled "Art of War") were creations of the learned academies of Qin. Their purpose was to, with a subtle but important re-definition of Wu-wei, engineer the end of the Warring States, and found the Empire of China. The whole story can be found in my just published "The School of Sun Tzu" - available here:
http://tinyurl.com/897kb6p