Ontological Absoluteness

I've been following the EFI project at Harvard.
Its a series of workshops "exploring the frontiers of incompleteness" which is mostly philosophy of set theory.
The next talk is by William Tait, so I had a look at his paper (the papers are made available in advance of the talks), and that paper lead to this post.

I have had this problem from time to time. I believe in the objective truth of statements of set theory (once you have specified which set theory you are talking about, by which I mean, once you have fixed the meaning of the language) but I don't consider myself a platonist.
I sometimes come across people who don't understand this.
They think that if you believe in the objective truth of set theory you must be a "Platonist".


So I look at Tait's paper, and he is talking about Wittgenstein's "Philosophical Investigations".  I didn't read it all, so I probably have the wrong end of the stick, but that doesn't matter, because what I'm writing about is some small change in my own thinking which came from it.  What I took him to be doing was arguing against the idea that for the semantics of set theory to be definite there must exist entities, the sets, which the terms in the language denote.  This is what Wittgenstein calls the "Augustinian" theory of language, and the Philosophical Investigations provides a critique of this theory.
Well, this is something which had occurred to me to.  Not that I worked it out in any detail, but it had occurred to me that reference to Wittgenstein would help people to understand that set theory could be quite definite in meaning, and hence that statements in set theory might have definite truth values, without there needing to be absolute truths about what sets there are.