They diverge as a result of repeated practice" (Analects 143). While both Confucius and Mencius believed that virtues could be developed, it was Mencius that approached the naturally arriving question of whether man is fundamentally good or bad. In turn, further questions arose in regards to his new founding principle on the goodness of human nature, such as, to what extent is human behavior conditioned by social institutions, and to what extent does it spring directly from innate qualities? Mencius' response delves not only into the principles on which his belief is found, but also the definition of the nature of man: what distinguishes humans from animals. .
According to Mencius, "Slight is the difference between man and the brutes. The common man loses this distinguishing feature, while the gentlemen retains it" (Mencius 91). In stating that there is a slight difference between man and the brutes suggests that they are essentially the same. However, Mencius believed that there was a difference that sets man apart from brute; this difference, or the "distinguishing feature" that the gentlemen is able to retain, is the heart. Without the ability to reason, humans and animals alike would be governed wholly by their "lesser" desires. It is this unique ability of rationality that is possessed only by man, which gives him, according to Mencius, the ability to have the moral goodness. To further illustrate, Mencius proclaims that, "Reason and rightness please my heart in the same way as meat pleases my palate" (Mencius 127). What he means, is that in tending to "sense organs" or the "lesser members" of man, such as the mouth and stomach, results in immediate gratification; however, in tending to the "greater member", the heart, he receives a pleasure that is equal to or even more than that of primal desires. In this ability to experience this higher pleasure, is in fact what sets man apart from animal, and so, even though the heart is only but a small component of the body, it is both unique to man, and considered as paramount.
