  A number of philosophers have suggested that what is distinctive of logical constants is their insensitivity to the particular identities of objects, or, more precisely, their invariance under arbitrary permutations of the domain of objects (Mautner 1946; Mostowski 1957, 13; Scott 1970, 160–161; McCarthy 1981, 1987; Tarski 1986; van Benthem 1989; Sher 1991, 1996; McGee 1996).