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What is multiple realizability?
Multiple realizability, in the philosophy of mind, is the thesis that the same mental property, state, or event can be implemented by different physical properties, states, or events.
Were there any notable people working on multiple realizability?
Hilary Putnam's best-known work concerns philosophy of mind. His most noted original contributions came in several key papers setting out the hypothesis of multiple realizability.
Did Hilary Putnam's papers on multiple realizability differ in opinion to established theories?
In these papers, Hilary Putnam argues that, contrary to the famous claim of the type-identity theory, it is not necessarily true that Pain is identical to C-fibre firing.“

Question: What was said about the theory?
Self-contained rewrite: What was said about the theory of multiple realizability?