The Art of War, written at the end of the Spring and Autumn Period, is the earliest surviving book on the art of war in China, and is said to have been written by Sun Wu, the general of the state of Wu at the end of the Spring and Autumn Period. Each of its thirteen chapters, with more than 6,000 words, begins with the phrase "Sun Tzu said", and deals with the topic in a central and hierarchical manner, with strict logic, concise language and a simple style of writing, making good use of prose to lay out the narrative, with vivid and concrete metaphors. The book summarises the experience of warfare in the Spring and Autumn period, emphasising military ideas such as "cautious warfare" and "knowledge", revealing the essence of warfare and some important laws, which had a great influence on the political, military and philosophical thinking of later generations.