 Explanations in cognitive science appeal to a many different kinds of mental representation, including, for example, the “mental models” of Johnson-Laird 1983, the “retinal arrays,” “primal sketches” and “2½-D sketches” of Marr 1982, the “frames” of Minsky 1974, the “sub-symbolic” structures of Smolensky 1989, the “quasi-pictures” of Kosslyn 1980, and the “interpreted symbol-filled arrays” of Tye 1991 – in addition to representations that may be appropriate to the explanation of commonsense psychological states. Computational explanations have been offered of, among other mental phenomena, belief (Fodor 1975, 2008 Field 1978), visual perception (Marr 1982, Osherson, et al. 1990), rationality (Newell and Simon 1972, Fodor 1975, Johnson-Laird and Wason 1977), language learning and use (Chomsky 1965, Pinker 1989), and musical comprehension (Lerdahl and Jackendoff 1983).