 A non-psychological account of sexual perversion, one closer to folk biology, claims that only reproduction allows us to distinguish perversions from non-perversions (Ruddick 1984: 287; cf. Gray 1978). This does not mean that every act has to be reproductive, only that natural sexual desires “could lead to reproduction in normal physiological circumstances” (Ruddick 1984: 288). Thus, a heterosexual couple having intercourse but not intending to procreate are not engaging in perverted sex: their desire is of the kind that, under “normal physiological circumstances”, could lead to reproduction (1984: 288).