This chapter argues that the crucial assumptions of Saul Kripke's argument, an objective principle of identity for mental-state types. This principle is actually compatible with both the type-identity theory of the mind and Kripke's semantics and metaphysics. The chapter presents a version of the type identity theory. The viability of the identity theory focuses on bodily sensations, such as pain and other states characterized by their phenomenal properties. According to Kripke, there is nothing in, for instance, pain which is not in apparently feeling pain. This argument has had a strong impact on the identity theory of the mind, both of the type and of the token versions. The gist of Kripke's argument has often been expressed as the idea that when it comes to pain and other bodily sensations, appearance and reality coincide. Kripke stresses that possible worlds are like stipulated situations.