David Armstrong’s law-maker, nomological necessity (N), is a second order relational universal that holds between state of affairs types, e.g., N(F, G). With only a small proviso, nomological necessity is supposed to instantiate as the causation of its second relatum, G, whenever its first relatum, F, instantiates.
In this paper, I will show that there is some friction within this theory when we consider that causal processes can be prevented and interfered with. The above mentioned proviso is supposed to handle these case but, so I argue, it fails to do so. — The critique here presented generalises to any theory of lawhood that utilises a kind of necessitation as lawmaker. Thus, Armstrong’s case can serve as a sample for all such theories.
Plausible means of resolving the difficulties will be presented.