  Since behaviorism is not a popular position these days, this application of an inverted qualia scenario is perhaps not so interesting. And given the complications discussed in subsection 2.3.1, there is even room for a behaviorist to resist. However, of considerably more interest are similar arguments against functionalism (and physicalism). Block and Fodor (1972), who invented the terminology of ‘inverted qualia’, were the first to formulate an inverted spectrum argument against functionalism, specifically Turing machine functionalism as defended in Putnam  1967.[30]  Ignoring the details of particular functionalisms, the argument is exactly parallel to the one against behaviorism. (Similar remarks go for the inverted spectrum argument against physicalism.) According to functionalism, mental states are functional states: states defined by their causal role with respect to inputs, outputs, and other states. So, according to functionalism, necessarily, two creatures who are functionally alike are also mentally alike. In order to complete the argument, an appropriate inverted spectrum hypothesis must be established, where Invert and Nonvert are functional duplicates.