 What courts and legal theorists have actually done in “modifying” the counterfactual test in these six ways is to propose quite different theories about the nature of causation. The INUS and NESS tests, for example, are in reality nomic sufficiency tests, a version of a generalist theory of causation that reduces singular causal relations to general causal laws and does not make essential use of counterfactuals (except insofar as counterfactuals are part of the analysis of the idea of a scientific law.) The substantial factor test, to take another example, is really the law’s version of a primitivist approach to singular causation, a version of singularist theories of causation in metaphysics. The necessary-to-chance modification is in reality the substitution of a probabilistic theory of causation for a purely counterfactual theory. It is thus a mistake to think that the law’s explicit definition of cause in fact—sine qua non—in fact evidences any deep or univocal commitment of the law to a theory of causation that is truly counterfactual in its nature (as is for example Lewis 1973a).