 The second realization definition of physicalism has been developed by Wilson 1999, 2011 and Shoemaker 2007. On this view, a property F realizes a property G if and only if (a) G has some set of causal powers or features S; (b) F has some set of causal powers or features S*; and (c) S is a subset of S*. (We may call this notion ‘subset realization’ to distinguish it from the different notion of realization just considered.) This suggests: 