 We have been looking at different ways of making sense of and justifying Davidson’s claim that mental anomalism stems from the constitutive role of rationality in mental ascription. In Davidson’s writings, however, another line of argument often surfaces which focuses less on the rational nature of mental events and more on their causal nature. As we have already seen, in his earliest work on action Davidson argued that reasons explain actions by causing them, and he later came to emphasize that what makes mental states and events what they are is determined in part by their causes and effects. Particular psychological explanations are causal (they invoke causes—Davidson 1963), and are formulated in terms of causally defined concepts (for propositional attitudes, see Davidson 1987b, 41; for mental contents, see Davidson 1987a, 44). In later work he frequently notes the anomic nature of causal concepts and causal explanations, and how mental properties and reasons explanations are anomic because of this—“reason-explanations…are in some sense low-grade; they explain less than the best explanations in the hard sciences because of their heavy dependence on causal propensities” (Davidson 1987b, 42; see also Davidson 1991, 162). If mental concepts are causally defined, and strict laws do not employ causally defined concepts, then mental anomalism appears to follow straight away, without need of any detour through issues concerning the rationality of mental concepts.