If every tribe is an interpretive community, and no tribe ever comes into contact with another one, then the problem does not arise. If there is only one tribe (as interpretive community), then the problem does not arise.
But in the contemporary world (I had almost said modern world), all these tribes, interpretive communities, denominations, nations, ethnic groups, and Texas are all jostling and bumping along along together. Because of this, there has to be a larger interpretive community that seeks to govern all inter-tribal interactions. There are the individual interpretations held by certain groups within the larger pluralistic set-up, but then there is the macro-interpretation that views this pluralistic set-up as a positive good overall, that sees neutral secularism as the sine qua non of continued civilization, and which insists on liberal democracy as the wise teacher that enrolls everyone into the great endless discussion of the Ultimate Global Seminar.
This macro-interpretation, which currently governs all public discourse, is the heart and soul of modernity. It has been the public face of modernity for three hundred years. Now, when people call themselves postmodern, are they really challenging this? Almost none of them are. But unless this is challenged, then the postmodernism is a complete sham.
Is postmodernism being urged as a new arbiter of all discourse between jostling interpretive communities. If it is the new arbiter, then why are the rules of engagement and discussion exactly the same as they were under modernity? Why has nothing changed? What is post about it?
In order for us to consider seriously that we have entered a postmodern era, we have to identify what has changed, if anything, at this macro-level. If the very reasonable reply is that nothing has, then perhaps we ought to be a little less exuberant about our pronouncements about the newly-arriving Age of Aquarius.
If the rules of discourse, policed by modernity, do not change, then it matters not whatever postmodern thoughts an individual man might think in his postmodern brain. Fine. Be our guest. But does modernity extend to that broader level, and does postmodernism require us to challenge it there or leave it alone? Yes or no?
If no, then drop the label postmodernism as a bad joke. If yes, then in whose name will you challenge it?