 It may be that there are some important, more general, physical similarities between the neural states of seemingly disparate creatures that satisfy a given functional characterization (see Bechtel and Mundale 1999, Churchland 2005, and Polger and Shapiro, 2012—but see Aizawa and Gillett, 2009 for dissent; this issue will be discussed further in Section 6). However, even if this is so, it is unlikely that these similarities hold of all the creatures, including Martians and other hypothetical beings, who could share our functional organization, and thus our theory of mental states would remain, in Block's (1980) terms, overly “chauvinistic”. One could counter the charge of chauvinism, of course, by suggesting that all creatures with lower-level states that satisfy a given functional characterization possess a common (lower-level) disjunctive state or property. Or one could suggest that, even if all creatures possessing states that occupy (for example) the pain role are not literally in the same mental state, they nonetheless share a closely related higher-level property (call it, following Lewis 1966 (note 6), “the attribute of having pain”). But neither alternative, for many functionalists, goes far enough to preserve the basic functionalist intuition that functional commonality trumps physical diversity in determining whether creatures can possess the same mental states. Thus many functionalists—both a priori and empirical—advocate role functionalism, which, in addition to avoiding chauvinism, permits mental state terms to be rigid designators (Kripke 1972), denoting the same items—those higher-level “role” properties—in all possible worlds. 