> "It just needs to" isn't a satisfying argument for me. Why does it
> need to be? (Warning: I'll mercilessly ridicule any appeals to
> "common intuition".)
I didn't say that suffering "needs" to be wrong (as I said before, I'm actually an error theorist, and believe that all moral claims are in some sense necessarily false). What I said is that arguments against cruelty to animals don't require the avoidance of needless suffering as the "paramount" moral criterion to succeed--they probably work so long as we give the avoidance of needless suffering any non-negligible ethical weight. In other words, you completely misread what I wrote.
> (Warning: I'll mercilessly ridicule any appeals to "common intuition".)
Normative ethics is all about intuition upon reflection, and not just in the classroom.
Here's a thought experiment to show that (intuitively) being a human isn't a requirement for moral standing:
Imagine that aliens were to land tomorrow. Let's suppose they were just like us, but a lot smarter and nicer--so nice, in fact, that they were entirely pacifistic. Would it be OK to raise their children in pens and slaughter them for food when they became meatier adults?
-- Luke