  Holistic theories of desire come in two main forms: functionalist and interpretationist. In the functionalist form, a desire is an internal state-type that plays enough of the causal roles suggested by (1)–(8) etc. (e.g., Lewis 1972). In the interpretationist form, desires are not treated as internal state-types found in a causal network. Rather, desires are treated as states of the whole organism, states that exist in virtue of the organism's displaying enough of the sorts of behaviors suggested by (1)–(8) etc. to be legitimately interpreted (in accordance with general principles of interpretation, such as a requirement to interpret creatures as means-end consistent) as having desires (e.g., Davidson 1980).