Most students who complete an Oxford DPhil in philosophy will have previously completed an Oxford BPhil degree (which is also a graduate degree, despite the name). In my experience, quite a few professional philosophers in the US have misconceptions about the BPhil and DPhil combination, misconceptions that are likely to lead to an Oxford graduate education being devalued. The Oxford philosophy department has a description of the BPhil degree here: http://www.philosophy.ox.ac.uk/admissions/graduate/bphil_in_philosophy

Interesting post, Jonathan. I don't see why the reasons primitivist must accept that there are no non-trivial necessary truths about reasons. When we think of other views where some kind of thing is taken to be metaphysically basic or some concept is taken to be unanalyzable (in terms of necessary and sufficient conditions, that is), we don't see philosophers accepting a ban on on non-trivial necessary truths. For example: Williamson (2000) claims knowledge is basic and that the concept is unanalyzable, but also makes a whole lot of interesting claims about it (e.g. necessarily, for X to be knowledge, X must be a safe belief).