Systematic argument in Chinese philosophy began with the Moist school, founded in the fifth century BCE by the first anti-Confucian thinker, Mozi (c. 470–c. 391 BCE). He laid down three tests for the validity of a doctrine: ancient authority, common observation, and practical effect. At first the controversies of the various schools over moral and political principles led to increasing rigor in argument; then to an interest in dialectic for its own sake, as evidenced in Hui Shih's paradoxes of infinity and in Kung-sun Lung's sophism "A (white) horse is not a horse"; and still later to the antirationalism.....