In ‘A New Route to the Necessity of Origin’, Rohbraugh and deRosset offer an
argument for the Necessity of Origin appealing neither to Suffciency of Origin nor to a
branching-times model of necessity. What is doing the crucial work in their argument is
instead the thesis they name ‘Locality of Prevention’. In this response, we
object that their argument is question-begging by showing, first, that the locality of
prevention thesis is not strong enough to satisfactorily derive from it the intended
conclusion, and, second, that the argument is not sound unless the Necessity of Origin is
operating as an implicit premiss.