 There is controversy about what the views of Yang Zhu (fifth to fourth century BCE)  were.[20]  However, a plausible case can be made that he defended ethical egoism based on a particular conception of human nature. Yang Zhu’s line of argument has considerable plausibility in his philosophical context. Although Mohists and Confucians disagreed about many things, they agreed on two key points: the proper Way to live and to organize society is dictated by Heaven, and this Way will sometimes demand extreme self–sacrifice of those who follow it. Yang Zhu invoked the notion of “human nature [rén xìng]” to drive a wedge between the former commitment and the latter. Yang Zhu appealed to the fact that nothing seems more natural for humans than self–preservation. But if there is a human nature, it must be dictated by Heaven, and therefore must be consistent with the Way. Consequently, following one’s instinct for self–preservation is actually the highest expression of Heaven’s will, and the self–sacrificing practices of the Confucians and Mohists are simply perversions of our Heaven–given nature. The Mohist response to this, as suggested by the example (cited above) of King Ling of Chu, was that there is no such thing as human nature; human motivations are highly malleable, and almost exclusively the products of environmental influences. 