  No one has argued that V&amp;V isn’t a useful distinction, but rather that scientists shouldn’t overinflate a pragmatically useful distinction into a clean methodological dictate that misrepresents the messiness of their own practice. Collaterally, Frigg and Reiss’s argument for the absence of epistemological novelty in simulation fails for just this reason.  It is not “a purely mathematical question” whether the solutions that the computer provides close enough to the actual (but unavailable) solutions to be useful. At least not in this respect: it is not a question that can be answered, as a pragmatic matter, entirely using mathematical methods. And hence it is an empirical/epistemological issue that does not arise in ordinary modeling.