I think that what Joseph is saying is that the question of how many people the Earth can sustain at level of resource expenditure X per person is independent of our ideas of what a just society should look like.
It might even be (gasp, horror) that our idea of what a just society should look like may have to adjust itself to whatever the answer to that question is (I think James' position is based on his irrational faith that his view of a just society must be realizable, no matter what).
--- On Sat, 5/2/09, Alan Rudy <alan.rudy at gmail.com> wrote: And are you really saying that the goals of science are simply to collect and generalized from the objective facts of nature? I like science and many scientists, but science is a social institution not an objectively empirical activity done by heroic (or normal) individuals. There's a ton of literature on this out there.