A. On disgust as a shrinking from mortality and animality:
Disgust concerns the borders of the body: the possibility that an offensive substance may be incorporated into and debase a person. The core objects of disgust are animals or their secretions above all feces, bodily wastes, and corpses, or creatures who have (or appear to have) related properties (ooziness, sliminess, decay). To put it very briefly, it would appear that disgust embodies a shrinking from animality and mortality, which, if taken in, would contaminate the human being who has a stake in rising above the merely animal.
It seems false that shrinking from slime, decay, and bodily wastes is a shrinking from mortality and animality. 1) It appears to be a healthy expression of animality. Slime, decay, and bodily wastes are often not healthy; they can be conducive to disease and infection. As a rough-and-ready way of avoiding contamination (literally!), disgust appears to be a natural expression - which is why we naturally feel it. Disgust in this sense is part of our being animals. 2) It isn't clear that feeling disgust at the idea of playing in your own feces (for instance) is a shrinking from animality and mortality, or that it has any connection at all with our "stake in rising above the merely animal". 3) Disgust in the sense Nussbaum is noting here is closely associated with the desire for cleanliness. While we do say that cleanliness is next to godliness, it seems to me to be completely silly to suggest (which Nussbaum does not suggest, but which I think would be required by Nussbaum's claims here) that a desire to be clean is an attempt not to be animal and mortal.
B. On the asymmetry of disgust and anger
Disgust is, then, very different from anger and indignation. Anger is about damage or harm. For that reason, it is very closely related to a central function of the legal system, namely, that of protecting citizens from harm, and punishing harms that occur. The reasons underlying a particular case of anger may, of course, be false or distorted; but if they stand up to scrutiny, we can expect the law to take an interest in them, and nobody would dispute the legitimacy of its doing so. Disgust is different. It is by no means clear that feeling grossed out by something gives the disgusted person a set of reasons that plausibly lead to making conduct illegal, especially when we note, as does Rozin, the irrational and associational thinking so often involved in disgust.
Disgust, too, can be treated as an issue of damage or harm, namely the harm or damage of being contaminated by something unhealthy. Likewise, we can reasonably expect the law to take an interest in lots of forms of disgust - disgust at garbage, disgust at feces. Since this paragraph immediately follows the above paragraph, the "then" in the first sentence means that we are to conclude from the paragraph discussed in (A) that disgust has nothing to do with harm in a way in which the law should take an interest. But the disgust considered in the above paragraph is sanitary disgust, and it is entirely reasonable to expect - even to demand - that the law take an interest in that. Nussbaum has switched, it seems, to an entirely different sort of disgust. This is a constant problem I have with all the arguments by Nussbaum I have seen on this subject: she fails to make distinctions between forms of disgust, and then goes on to use that equivocation to deny parallels between anger and disgust. I'm hoping this is avoided in her book, which I'll be reviewing here when I finally manage to locate a copy. (Note also that she provides no argument here for disgust being different - it is merely asserted.)
C. Disgust at persons vs. disgust at actions
While there isn't any quotable quote on this point, in this article Nussbaum continues to consider only disgust at persons, not disgust at actions. But the two, it seems, need to be considered as rather different. Disgust at the rape of a child is not in the same moral category as disgust at Jews: there is an entirely different patterning of reasons associated with the two.
As I said, I hope eventually to find a copy of her book on this subject and review it here. But, as I said about her Reason interview, I'm not heartened by Nussbaum's article.