Xunzi's Systematic Critique of Mencius

Some commentators hold that Xunzi's criticism of Mencius' thesis that human nature is good depends more on Xunzi's definition of xing or nature than on substantive argument. Some also claim that Xunzi is committed to accepting Mencius' thesis. A more precise account of Xunzi's critique is offered here, based on an elaboration of his distinction in the "Xing e pian" between ke yi (capacity) and neng (ability). Others have noted this distinction, but no one has sufficiently appreciated its role in making Xunzi's critique more systematic and substantive than it is usually thought to be.