Camosy on Singer, personhood, and Christianity

Prof. Charles Camosy, who blogs at Catholic Moral Theology (link), has a piece in the latest Commonweal on the "evolution" of Peter Singer.  He writes, "[C]an Christian ethicists talk with Peter Singer—and can he talk with them? Are they even intelligible to one another?  The answer, it turns out, is yes."  Later in the piece, Camosy adds:

Until recently, Singer’s theory would have forced him to describe persons as merely self-aware bundles of contingent preferences, but his recent shift [RG: described in the essay] creates new space for models of personhood that are compatible with Christian ethics. According to one such model, persons are kinds of things that persist over time, require objective goods to have a happy and meaningful life, and are defined in morally significant ways by their relationships with parents, friends, spouses, and children. If Singer could accept that definition of personhood, or even just part of it, much of his disagreement with Christian ethics would disappear.

In my experience, Charlie is admirably eager to see the good, and the potential for good, in others' views.  I have to say, though, that I think the "if" in that last sentence is a big one.  It sounds a *bit*, as one friend of mine put it, like "If Singer could accept Christian moral anthropology -- which he does not and cannot -- then his disagreement with Christian ethics would disappear."  But I think Singer's account of "speciesism" (which Camosy describes) is not reconcilable with the definition of "personhood" on which Christian ethics is built.

Thoughts?  Note:  Peter Singer's views on many issues are, in my view, horrifying.  There's no need to observe, in the comments, that he has very very wrong views on some important questions.  Let's stipulate that he does, and ask, first, whether Prof. Camosy is right when he says that "[t]he recent shifts in Singer’s thinking suggest that he and Christians may soon have more fruitful ways to talk about their disagreements.  Meanwhile, there is already enough practical agreement for Christians and Singer’s followers to work together on problems that cannot wait until every theoretical question is settled."  Next, let's ask whether, actually, cooperation with "Singer's followers" actually does have to wait until that cooperation no longer requires Christians to put aside the non-trivial matter that Singer's followers believe that severely disabled neo-nates, whose care is expensive, may (should?) be killed.  On the one hand, of course Christians can and should cooperate for shared ends with people who are not Christians.  But, are there limits?  I'm not sure . . .