Leiter on Smith on the terms of academic discussion

The blogosphere is abuzz with discussion of Steve Smith's short essay, Jurisprudence: Beyond Extinction, which I posted here earlier.  Jeff Lipshaw defends the essay here, Larry Solum questions it here, and Brian Leiter expresses his, um, not so positive views here.  One of Leiter's arguments should be of special interest to MoJ readers.  Smith wrote that:

[U]nder modern conventions, academic discussion is supposed to be carried on in secular terms, meaning, for the most part, the terms of scientific naturalism and of common sense everyday experience.  In attempting to explain som ehappening or phenomenon, it is perfectly permissible for modern scholars to refer to religion--or to people's beliefs in God.  By contrast, actual appeals to God, or to anything that looks metaphysically suspicious or exotic, are out of bounds.  As a result of this drastic narrowing of the range of admissible argument or explanation, claims or positions that would once have been framed forthrightly in theological terms now must be translated into more secular terms--or else abandoned.

Leiter comments:

I take it the "modern convention" of discourse in the post-Enlightenment world is that claims should answer to reasons and evidence, and that dogmatic appeals to authority--whether God's or Aristotle's--will not suffice to establish the truth of some proposition.  There is no doctrine of "scientific naturalism" accepted by contemporary participants in jurisprudential debate (Raz has even famously criticized Hart for the naturalism in the background of The Concept of Law), though certainly not everything is thought to count as a reason or as pertinent evidence.  Contemporary "academic conventions" aren't just picking on Smith's God or Blackstone's; Osama bin Laden's God is out too.  So, too, is my pet theory that positivism is true because I say so.  Also the view that nothing is law if it does not comport with the hidden lyrics on the Beatles' Abbey Road album.  Also it is not evidence that natural law theory is false that it gives my Uncle Bert gas.  And so on.

I'm not quite sure how to describe what makes these varoius boundaries of rational disputation hang together; and one must recognize, of course, that these boundaries are themselves always in dispute.  But it is really weird at the dawn of the 21st century, several hundred years after the scientific revolution and the Enlightenment, to find a professional scholar seriously suggesting that it constitutes a "drastic narrowing" of argument to not take seriously dogmatic invocations of the deity in intellectual inquiry.  What exactly would "argument and explanation" in Smith's world look like?  What would constitute a response to his imagined academic who stands up at a conference and invokes Blackstone's idea about God's law? 

Of course, we know what intellectual discourse looked like when dogmatic invocations of the deity were thought to constitute an argument.  And there is a reason those cultures and eras were not ones notable for their great number of intellectual insights and advances.