Sun Tzu proved on the battlefield that his theories were effective (for example, at the Battle of Boju), that he had a successful military career, and that he wrote "The Art of War" based on his tested expertise. However, the "Zuozhuan", a historical text written centuries earlier than the "Shiji", provides a much more detailed account of the Battle of Boju, but does not mention Sun Tzu at all. Beginning around the 12th century, some scholars began to doubt the historical existence of Sun Tzu, primarily on the grounds that he is not mentioned in the historical classic "Zuo zhuan", which mentions
Tzu Chi Chi International Medical Association (TIMA) and also the Tzu Chi Collegiate Youth Association (Tzu Ching) (慈濟大專青年聯誼會 (慈青)), Tzu Chi volunteers and relief workers are mostly recognizable worldwide by their blue and white uniforms called, in , "lántiān báiyún", ( lit. 'blue sky, white clouds'). The foundation's work includes medical aid, disaster relief, and environmental work such as recycling. While Tzu Chi has a policy of being secular in its humanitarian work, Dharma teachings are often integrated into its practices for volunteers. Cheng Yen is considered to be one of the "Four Heavenly Kings" of Taiwanese Buddhism, and Tzu Chi itself