As you have probably noticed, I am teaching Mencius this semester.  Right now I am reading a batch student papers, most of which are on Mencius (some are on the Analects).  In one paper, a student was grappling with the questions that arise in chapter 11 (or 6A), where Mencius is debating about human nature with Gaozi (Master Kao).  A key element of this debate is whether or not Duty (yi – also translated as "appropriateness") is internal.

I tend to take the position that Mencius and his followers are arguing that, yes, Duty is internal and they refute Gaozi's attempts to prove otherwise.  People with much deeper knowledge of Mencius than me disagree, however.   Kim-chong Chong  argues that Mencius never really establishes that Duty is internal; rather, Mencius seems to be, on this account, resisting the idea that Duty and Humanity can properly be understood in terms of "internal" and "external."  James Behuniak comes closer to the position I will argue below, but even he says: "Mencius does not argue here or elsewhere that appropriateness [yi] is internal…"

Of course, one of Mencius' defenders, Adept Kung-tu, does argue that Duty is internal (11.5; 6A.5), but let's say that Chong and Behuniak are correct, as least insofar as there is not an explicit affirmative argument attributed to Mencius himself that "Duty is internal."  What I would hold, however, is that the clear implication of the text as a whole is that Duty is crucially, though not wholly, internal.  I say this for two reasons.

First, the metaphors used in passages 11.3 and 11.4 (6A.3 and 6A.4) suggest that human nature includes something like an appetite for Duty.  Both passages end with suggestions that our love of food – roast meat or broth – is relevant to the way we should understand Duty.  This might be framed in terms of preference – my preference for roast meat does not depend upon who cooks it.  But food entails more than mere "preference."  We have a certain appetite for food.  It wells up from within us when we are hungry, and we must satisfy that deep internal urge.  Mencius thus could be saying that we have an appetite for Duty, we hunger for it, we have a deep and abiding internal urge to fulfill our obligations toward others.  This may be an optimistic view of human nature, but I think it is what the text is trying to convey: Duty is internal.

Of course, the more particular definition of Duty will depend upon "external" circumstances. The unusual factors of Shun's life led him to understand that his filial obligations required disobedience to his parents.  So, Duty is not wholly internal.  But that internal drive to do the right things by others is, I would argue, more fundamental.  It is what drove Shun to stay faithful to the idea of being filial, even when his parents acted so badly.  It is, in the minds of the authors of the Menicus text, the originary emotional constituent of Duty.

Second, other aspects of the text strongly support the idea that Duty is internal.  Most importantly, perhaps, would be the famous assertion that human nature is basically good in passage 3.6 (2A.6): "Mencius said: 'Everyone has a heart that can't bear to see others suffer…..'"

The passage describes four aspects of "heart" (or, "heart-mind" – xin): we all have a heart of compassion, a heart of conscience, a heart of courtesy and a heart of right and wrong.  These four internal elements of basic human nature are the "seeds" of key Confucian principles.  For our purposes here, we should note: "A heart of conscience is the seed of Duty."  Thus Duty arises from, is cultivated from, a seed inside of us.  It grows from within.  And just to drive the point home:

These four seeds are as much a part of us as our four limbs.  To possess them and yet deny their potential – that is to wound yourself…

I  do not mean to deny the careful arguments of the scholars mentioned above.  It may be true, that in terms of stricter logical analysis Mencius and his followers never quite fully refute the assertions of Gaozi.  But the text provides sufficient grounds to support the notion that Mencius wanted us to believe that Duty is internal.