Mencius is said by the historian Sima Qian to have studied with Confuciuss grandson. In his discussion of qi, Mencius departs from his contemporaries understanding of the concept by stating that the method of cultivating qi lies in regular moral practice: it is engendered by the accumulation of righteousness and is not obtained through sporadic righteousness. In Menciuss view, Yi Zhi was well served by following his unstated impulses, since they were pushing him in the right direction. The notion that the bedrock of morality lies within natural human impulses is typical of Mencius, and informs his most important area of departure from Confucius: his theory of human nature. After enumerating the Four Beginnings of humanity, righteousness, ritual and wisdom, Mencius intones the same warning: Humans have these Four Beginnings as we have our four limbs. Mencius never tolerates false pretexts or mere velleities when it comes to the serious business of moral self-cultivation.