The Art of War, Sun Tzu

Sun Tzu's The Art of War is a series of lessons in the applied art of problem solving. 

Sun (544 BC-496 BC), an experienced general from the Warring States period of Chinese history, saw war as an inevitable problem – indeed, the ultimate problem confronting the state. The Art of War summarises his lessons on how to solve the problems raised by conflict.

The work comprises a series of pithy discussions of the different strategic situations that might arise, and the best responses for each. In many ways it is a masterclass in the application of critical thinking to practical affairs. 

Aspiring generals are advised to 'appraise the situation' according to five separate criteria, and to plan accordingly. 'The expert at battle seeks his victory from strategic advantage', Sun writes, so every general must assess their situation from every angle, and establish not only the best way to give themselves the strategic advantage – but also of preventing the other side from giving itself the advantage. Throughout the text, Sun epitomises the qualities of a good problem solver by focusing on the nature of the problem; asking productive questions about it; and making sound decisions.