- Mencius, Hume, and Sensibility Theory
In this article I will present and defend sensibility theory, a particular version of naturalistic moral realism, by combining the complementary features of the Mencian and Humean traditions. Moral irrealism stresses subjectivity. Traditional moral realism stresses objectivity. What distinguishes sensibility theory from other metaethical theories is that it harmonizes subjectivity and objectivity on a realist ground.
I bring Mencius and David Hume together in defending sensibility theory because this theory derives essential support from the works of both. Mencius (371-289 B.C.) is one of the most important Confucians in the classical period of ancient Chinese philosophy. He helped to shape the Chinese philosophical thinking after him for more than two thousand years. Hume (1711-1776) is one of the best-known Scottish philosophers who even today still greatly influences almost every field of Western philosophy. Mencius and Hume share essential features in their moral theories, yet they are also complementary to each other at other fundamental points.1
Mencius insists that moral qualities are as real as secondary qualities. He frequently compares the mind/heart's (xin) enjoyment of moral qualities to the eye's enjoyment of certain colors, the ear's enjoyment of certain sounds, the mouth's enjoyment of certain flavors (Meng Zi 6A4, 6A7, 6A16).2 In this regard (and in many others), Mencius is similar to Hume. Hume says, "Vice and virtue . . . may be compar'd to sounds, colours, heat and cold" (A Treatise of Human Nature, p. 469).3 Secondary qualities contrast with primary qualities. The latter are physical properties such as mass, shape, electrical charge, and the logical constructions of these physical properties. The former are dispositions to produce sensory experiences of certain sorts under certain conditions.
Secondary qualities have traditionally been held to be different from primary qualities in explaining the fundamental causal structure of the world. Nevertheless, their ontological and epistemological place is secure by virtue of their presence in experience and the existence of a well-articulated "space of reason" regulating their application. Hume says, "Though it be certain that beauty and deformity . . . are not qualities in objects, but belong entirely to the sentiment, internal or external, it must be allowed, that there are certain qualities in objects which are fitted by nature to produce those particular feelings" ("Of the Standard of Taste," par. 16). According to Mencius and Hume, moral qualities, like secondary qualities, are conceptually tied to certain human sensibilities; that is, they are response-dependent. This position has been called sensibility theory by contemporary ethical writers.4
The analogy between moral-quality experience and secondary-quality experience can be presented at two levels. (a) In the case of secondary-quality experience, [End Page 75] the response of the subject (or perceiver) to an object in the first instance serves as the ground for ascribing a secondary quality to the object. Similarly, in the case of moral experience, the response of the subject (perceiver or spectator, in Hume's terms) to an object in the first instance serves as the ground for ascribing a moral quality to the object; even though the "moral" response may be more complicated in structure. (b) Correction (by reflection or reason) then occurs both with the response to secondary qualities like redness and with the response to the ascribed quality of being good (e.g., being virtuous).5
Inspired by Hume, contemporary writers John McDowell and David Wiggins, among others, have made important contributions to sensibility theory in explaining objectivity in ethics. The theory they offer, while revealing, presents difficulties of its own. Its central claim, "x is good/right if and only if x is such as to make a certain sentiment of approbation appropriate," is non-informative in fundamental ways. This is so because the claim involves what philosophers call an explanatory circularity. In what follows, I clarify and defend a particular version of sensibility theory. I show that the problem of non-informativeness faced by McDowell and Wiggins can be overcome by introducing a combination of Mencius' and Hume's complementary theories of human nature and moral psychology. In conclusion, I examine possible objections to the theory I defend.