"Two Chinese Philosophers", which appeared in 1958, was the first book by the late Angus Graham, who went on to establish a reputation both as one of the leading sinologists of the 20th century and as a creative philosopher in his own right. In the course of a scholarly career spanning more than 40 years, Graham became known as a thinker and interpreter of extraordinary depth and incomparable breadth. Since the initial publication of "Two Chinese Philosophers", the field of neo-Confucian studies has proliferated, yet Graham"s work on Ch"eng Ming-tao (Ch"eng Hao, 1032-1085) and Ch"eng Yi-ch"uan (Ch"eng Yi, 1033-1107) has not been superseded. The Ch"eng brothers were leading exponents of the neo-Confucian revival, which became orthodox state doctrine, used thereafter for the training and ideological moulding of the Chinese ruling class.