 It is on the basis of this universal law that Fechner’s theory has been described as “materialist” (Heidelberger 2004: 98, 107). This is an odd description, though, because the law seems to postulate that the mind has an efficacy on the body rather than the conversely. Materialist theories are often epiphenomenal, allowing the causal direction to move only from the body to the mind. But Fechner’s law seems to say the opposite. 