 As noted, the epiphenomenalist worry arises from two points that are absolutely basic to Anomalous Monism—first, that mental events are at the same time physical events, and, second, that while mental predicates cannot figure into strict causal laws, physical predicates must. Early critics moved quickly from these points to the epiphenomenalist conclusion that mental properties are causally irrelevant, because there are always strict law properties—physical properties—to causally explain the occurrence of an event. (For detailed discussion of this line of argument, see the supplement on  Mental Properties and Causal Relevance.)  Among many other problems with this line of argument, however, there is the one immediately capitalized on by Davidson: that within the extensionalist metaphysical framework in which Anomalous Monism is developed  (2.1  above), properties don’t cause anything, and so can be neither causally relevant nor irrelevant. According the Davidson, only events are causal relata. He expresses general skepticism about epiphenomenalist objections to Anomalous Monism that depend on the idea that events cause ‘by virtue’ of the properties they instantiate (Davidson 1993, 6, 13). This is closely connected to his sharp distinction between causation—a metaphysical relation between particular events independently of how they are described—and explanation—which relates events only as they are described in particular ways. But as we will now see, this doesn’t end the concerns about epiphenomenalism. (For related discussion concerning epiphenomenalism and its bearing on the relationship between Anomalous Monism and human freedom, see   Related Issues: 3.2 Anomalous Monism and Contemporary Compatibilism.)