The authors such as Papineau and Block and Stalnaker mounted a general critique of the thesis that property identities are closely connected to reductive explainability. Kim takes Putnam to argue that identity claims are ideally suited for the role of connecting principles or bridge laws. These identity claims are thus justified by the fact that they enable the reduction of classical thermodynamics to statistical mechanics, and in this way contribute to a substantial simplification of the physical picture of the world. Broad developed a view of mechanistic, i.e. reductive, explanation that, in many respects, is very similar to that of Levine. For Levine, reductive explainability is connected with claims about the identity of properties. Frank Jackson has in recent times given an interesting new twist to the debate about physicalism. Reductive explainability in Broad's sense implies reductive explainability in Jackson's sense, but not vice versa.