Originally Posted by Kevin-W:
One does not "allow" house cats to hunt.
Sure one does. The choice to keep a cat as a pet is to allow it to hunt. If you think the trade-off is worth it, (cat-caused dead animals Vs cat companionship) then you'll keep a cat. If you don't think it worth it, then you won't keep a cat. Cats can't help themselves, but we get to make the choices.
Disclaimer: I don't keep a cat. One reason is the whole hunting thing.
Cats, whether they are kept by nice old spinsters or not, hunt. Cats would still hunt cute little voles and shrews regardless of whether humans had domesticated them or not. "Ownership" of a cat and its predeliction to go out and kill things are not linked, and they are certainly not dependent on each other.
Of course you could keep a cat indoors all the time but that seems a bit cruel - not to mention expensive (cat litter's not cheap you know). I bet you wouldn't advocate doing the same to a dog. In any case, keeping a cat indoors does not really alter its fundamental nature (at least in the short and medium terms) as a predator. It's a killer. Nature, red in tooth and claw and all that.
Unless you're advocating bumping off all cats to prevent any more frogs and birds being killed. Which is almost as silly as your suggestion that there is a moral equivalence between keeping a cat and shooting lions and other large animals for sport.