Basically what's going on here is the author is working with the Hegelian concept of the Absolute - which is normally capitalized, but isn't here for some reason? Along with the Kantian and Heiddegerian conceptions of objects hence why they keep saying "itself" all the time. I'd have to actually read the book to understand much beyond that.
The point of the above tract is that traditional conceptions of the Absolute are, by some hand-waivey thought-magic, not actually all that absolute, and that the *real* Absolute is existence (material existence) itself or, dare I say, Dasein.
So, basically, you'd need to have taken a few collegiate level philosophy courses to really get at what he's talking about. His word choice is, I would assume, also influenced by having read Wittgenstein and some of the other "analytical philosophers".
I can at least respect this - when I was a freshman in college there was a course I had to take called "FYC" First Year Colloquium - basically a class on how to take college courses and to make sure we could all write papers properly and understood how to cite things. We had to read this shitty god-awful self help book called "the identity code" - which at the time the only amazon review for it was written by the author's wife. I do understand now what they were trying to get at - since much of the angst felt by 15+ year olds is actually a classical identity crisis, but captain corporate self-help didn't really get that point across in a meaningful way. So I read the book as the course required, and then took it out back and shot it several times with my Mosin Nagant and brought it to class in that ruined state for the rest of the semester.