Well, it's a big argument and I haven't read it in awhile, but the question is whether we should expect scientific explanations to have a natural end point at which there's nothing left to explain. If science were perfectly objective, and nature were reducible to some material stuff that's at least half-way intelligible, we should expect human science to run out of things to explain at some point. Or at least we'd run out of our capacity to understand what the universe has to offer.
But if science has a pragmatic aspect and is motivated by the promethean or luciferian desire to control the environment, and we never rein in that motivation or change our nature, we can expect scientific "explanations" to continue forever, because we'd always be unconsciously looking for better ways to tame or humanize nature. Science would stop in that case only when the universe has been turned into an artificial playpen or when we've eliminated the world-as-scary-wilderness.