If at the heart of this moral realism we find a peculiar brand of Thomism, then the recovery of Thomism, however specifically articulated, might be at the heart of a postmodern conservatism. If at the heart of any postmodern conservatism is the excavation of the Christian categories that modernity claimed to repudiate but instead subsumed, then American postmodern conservatism (and yes, the nomenclature is becoming unwieldy) might be central to any rethinking of conservatism itself. [italics mine]
In this case, "postmodern" functions as a historical marker rather than a specific body of thought. I'm not sure what the call to return to Thomism would mean if we were also to read the postmoderns. Rather, this seems like a call for limited deconstruction: let's see the past for what it is, and preserve (or re-vivify) what we can. Two points:
1. As I remember After Virtue, MacIntyre claims to be doing something along these lines. Does he fit in the definition of postmodern conservatism?
2. Charles Taylor claims (in The Sources of the Self, and I think also in A Secular Age) that, having made the transition into modernity, there is no going back--not in the same form, anyway. Having eaten from the tree of the knowledge of good and evil, one has to leave the garden. Certain things--not entirely bad--come as a consequence of this, even if the loss is real and not to be underestimated. Obviously, I'm not as hostile to Locke--and not entirely sure how our founding can be described as an 'American Thomism'--but the success of this project depends, as a historical matter, on bringing the philosophy to which we should return as close to the present day as possible.