According to Mengzi, “to fully apply one’s heart is to understand one’s nature” (Ivanhoe, 2005, p. 152). While this may, upon first reading, seem to be a difficult saying to understand, it is made very clear if one further examines Mengzi’s ideas concerning what it means to be human and what is the nature of humanity.
Although Mengzi acknowledged that not all humans were good, he nonetheless believed that human nature was itself inherently and intrinsically good. He reconciled the seeming disparity between the reality that some humans are not good and his idea that human nature is good by pointing out that not all human beings fully develop their potential.
Mengzi located all potential human dispositions as existing inherently in the human heart. He pointed out, for instance, that all humans have the seeds of respect and compassion within them. According to Mengzi, “we inherently have them” and “it is simply that we do not reflect upon them” (p. 148). One cannot, then, blame one’s nature for possessing some flaw that makes one disrespectful or lacking in compassion. Rather, it is that that person did not develop the potential that was in him inherently.
Similarly, Mengzi located even the elements of human nature that seem to lack in or work contrary to virtue as dwelling inherently in the human heart. For example, he believed that disdain is naturally found inherently in human nature. However, in his belief that human nature is inherently good, he found a positive use for these seemingly negative features of what it means to be human. With the example of disdain, for instance, he located the beginning of righteousness and with the example of disapproval he located the beginning of wisdom. In this way, Mengzi was able to concede that there were elements in human nature which were there inherently and were commonly viewed as negative features or as vices but still hold to his view that human nature is inherently good because these apparent vices were intended for a good purpose.
Mengzi deftly walked a line that allowed him to maintain three positions which others had attempted to juggle in the past but failed to adequately account for: the first, that human nature is inherently good; the second, that there are elements which reside inherently in human nature that might be called vices; and, third and finally, that each individual human being is responsible in very large part for the development of his own nature. In his theory that the virtues and the vices, the latter of which are intended to serve the former, lay in human nature in seed form and that each person must develop them within himself, Mengzi found the means by which to explain and account for all three elements.
Ivanhoe, Philip J. and Bryan W. Van Norden. (2005). Readings in classical Chinese philosophy: Second edition. Indianapolis: Hackett Publishing Company, Inc.