Credentials for "Interdisciplinary" work

Much of the conversation on Mirror of Justice -- indeed, the blog's "mission" -- and much of the work of our bloggers is "interdisciplinary."  So, take a look at the conversation going on between Prawfsblawg's Dan Solove and Professor Brian Leiter about whether "interdisciplinary" work by law professors without Ph.D.'s is worth anything.  I'm with Solove, but perhaps that is just because, in my own experience, the "you need a Ph.D. in ___ to really explore ___ with any competence" argument is one that is too often wielded inconsistently and disingenuously.

Rick