Disgust, repugnance, and fears of impurity have made three appearances in The New York Times over the last few weeks. OK, it's not Britney, but still. For an abstract concept, three is a lot.
First, as I wrote about before, we have Stephen Pinker's essay, The Moral Instinct. There, Pinker says early on that, psychologically speaking, there are (roughly) five distinct sources of moral sense: not harming others, being fair, being loyal to a community or group, respecting authority, and purity.
Later in the piece, Pinker says that the excessive pursuit of purity can be a source of moral illusions: those who are against cloning because it gives them "a moral shudder," he says, just aren't being thoughtful or reasonable enough. It's a kind of prejudice.
I was struck at the time: how can disgust be a source of moral judgment and also be a distorting factor on moral judgment?
Then there was this recent short item in the Arts section: "Economists Dissect the 'Yuck' Factor." Here, Patricia Cohen points out that disgust is a complex issue for conservatives: on the one hand, economic conservatives favor fewer limits on markets, so the fact that you feel grossed out by, say, kidney purchasing or baby buying is simply not relevant to whether these things are good or bad. On the other hand, social conservatives (as Pinker points out) frequently invoke the moral shudder in explanations of wrongness.
As she tells the story, economists say that everything should be open to markets unless you can prove otherwise, while skeptics say that the burden of proof is on the other side -- that if you want to open up a market, you must make a case for the morality of the proposed transactions.
Interestingly, she cites Pinker's essay as one source of the idea that disgust is an "early warning system" -- a feeling that alerts us that something needs moral scrutiny.
On this view, the answer to my question is that disgust is a not a source of moral judgment, but is merely an indicator, and when trusted, acts as a distorting factor.
This answer is supported by the third appearance of disgust, in the pyschologist Paul Bloom's review of a new book by philosopher Kwame Anthony Appiah. There, Bloom summarizes some research as showing that disgust and other emotions cause us to make judgments we later find we cannot justify.
Interestingly, this approach almost seems to side with the economists, insofar as the suggestion is that if one cannot give a justification in terms of other factors -- such as harm -- then disgust is irrelevant.
I'm no fan of purity obsessions, believe me. But at the same time, I also think we humans are not always very good at figuring out what's good for us -- as I've said before, once we start doing cost-benefit analysis, we tend to start estimating wrong.
I'm left uncertain over whether, and when, and how, to care about disgust. If a poor man risks his life selling a kidney to a rich man and then gets sick and dies, I feel a kind of disgust. I'm inclined to take my reaction as morally significant whether or not I can back it up. But I know that some people feel a kind of moral disgust at sexual freedom, homosexuality, and so on, and there I feel, well, no, that's not morally significant.
I suppose ideally I would be able to articulate in other terms what is bad about free markets for organs donations. But in the meantime, what am I supposed to do? It's not like cost-benefit analysis has such a great track record, either.