Whether “pure” and “purity” are best associated with the aesthetic or the moral is open to question. In a recent article, Jonathan Haidt and Fredrik Bjorklund have listed the purity/sanctity as one of five evolutionary foundations of ethics.[i] They include the concept of “cleanliness” under the concept of pure/impure. Purity is one of what they refer to as an “innate moral nodules.” The other four nodules are clearly non-aesthetic, i.e. harm/care, fairness/reciprocity, and authority/respect. (Of course all of these elements could have an aesthetic side or be mixed in some way with aesthetics. For example authority could be gained or exhibited through a certain style of clothing.) Sanctity also seems to be outside the domain of aesthetics. We do not say that something is holy or sacred and mean by that that it has an aesthetic property. (Again, the look of sanctity might however be aesthetically pleasing.)
So, is purity basically a moral matter and not an aesthetic one? Haidt and Bjorklund recognize that the issue is controversial as they note that liberal moral theorists often see these as matters of social convention or of prejudice and not as matters of morality. Still, such moral theorists would probably not see purity as a matter of aesthetics. I think that Haidt and Bjorklund are right that matters of purity are “legitimate parts of the moral domain.”[ii] For example, if one takes pride in the “purity” of one’s blood-line, there doesn’t seem to be anything aesthetic involved, and even though I, as a liberal, do not approve of the morality involved, I can see how others might see this as a moral matter. This does not mean however that purity is never a matter of aesthetics. The Japanese emphasis on the value of purity would seem to be aesthetic. The “aesthetic of purity” is a common theme for their culture.[iii]
By contrast, most mentions of “purity” in the Journal of Aesthetics and Art Criticism have to do with whether or not there are such things as pure art forms and whether or not there is a pure aesthetic attitude. Clive Bell and Clement Greenberg are commonly referred to as people who favor purity in the appreciation of art. Purity is commonly associated with formalism.
But the question of whether purity is itself an aesthetic quality is seldom addressed. If the pleasurable response to purity is directed to the perceptual features of the object qua perceptual then the experience would seem to be aesthetic. Thus there is reason to believe that “pure” can be an aesthetic quality.
[i] Haidt, J., & Bjorklund, F. “Social intuitionists answer six questions about morality” in W. Sinnott-Armstrong (ed.), Moral psychology, Vol. 2: The cognitive science of morality (Cambridge, MA: MIT Press, 2007) pp. 181-217.
[ii] Pg. 203
[iii] Kenneth G. Henshall. Dimensions of Japanese Society: Gender, Margins and Mainstream (Palgrave Macmillan, 1999) pg. 179. Henshall notes that the Japanese concept of purity can also include notions of perfection and normalcy. He observes that in Japan the adult male who fails to gain a job is considered aesthetically impure.