Good afternoon, Professor.
Thanks for leaving a comment on my blog. I'd return the favor, but I see that you do not have commenting software on yours.
Re the Bestiality post...I would assume that Singer doesn't object as long as the animal is not hurt or "protesting" in some way. But, as you know, he's really weird. :-)
I think also he's trying to make the point that you can't object to sex with animals on cruelty grounds if you think it's okay to stuff them in cages, kill them and eat them. You can't object via a cultural relativity argument, as some cultures (apparently) have engaged in it. You can't object via a "people have souls" appeal to religion because we also have bodies, bodies that are very similar to animal bodies. A Kantian "people have dignity" argument fails because we do other things that counter our alleged dignity.
So, why does this sexual taboo stand when so many others have fallen? I don't think Singer actually answers the question. He simply wants to show that there isn't a good argument against it.
Esoteric, adj. Very particularly abstruse and consummately occult. The ancient philosophies were of two kinds,--exoteric, those that the philosophers themselves could partly understand, and esoteric, those that nobody could understand. It is the latter that have most profoundly affected modern thought and found greatest acceptance in our time.
(Ambrose Bierce, The Devil's Dictionary, c. 1911)