 This quote suggests a connection between type-identity theories and models of theory-reduction: It suggests that reduction, understood as an inter-theory relation, is closely related to type-identity theory. The idea seems to be this: Within a future psychophysiology, the fact that mental types are identical to physiological types might be revealed, and the nature of mental states will ultimately be given in terms of psychophysiology, rather then in terms of psychology. Similar positions have been held by Place (1954, 1956, 1960), who primarily speaks of constitution rather than identity, whereas Smart explicitly stated this thesis in terms of identity (Smart 1959).