The Book of Lord Shang (商君书, Shang Jun Shu) is the most important and well-known text of the Legalist school of Chinese philosophy. It was written over a period of about 100 years during the Warring States Period, lasting roughly 400 BC to 200 BC. Though it is traditionally attributed to Shang Yang, and he did indeed appear to have written part of it, the last few chapters refer to people and events which didn't occur until after his death. Compare and contrast The Prince.