Explain Putnam's objection to the identity theory. Why does he think that functionalism improves on the identity theory? Is he right about this?

In Hilary Putnam's, "The Nature of Mental States", he deals with the question of whether or not pain is a brain state or "Is the property of having a pain at time t a brain state?" (Putnam). Throughout the article, Putnam goes on to argue that to claim pain as a brain state is not an identity claim. This can only be accurate if the specific pain is a specific brain state, or "being A …

…brain state?" (Putnam), by clearly giving valid arguments against the identity theory and verifying that functionalism is a clear cut path for such a question. Through functionalism, Putnam confidently shows that "pain states are brain states" through knowledge which has been independently justified with examples of both existent and nonexistent beings, as well as inanimate objects, all which exclude experience. Functionalism is a non-competing measure and solution to the "pain states are brain states" problem.