 In his early writings, Helmholtz defends a broadly Kantian methodology against a more far-reaching idealism. In “On the Relation of Natural Science to Science in General”, Helmholtz opposes Kant to Hegel. Helmholtz argues that for Kant “a principle discovered a priori was a rule applicable to the method of pure thought, and nothing further; it could contain no real, positive knowledge” (Helmholtz 1995 [1862], 79). For Hegel, on the other hand, “not only the physical phenomena, but even the actual world…were the result of an act of thought on the part of the creative mind” (ibid.). As a result, according to Helmholtz, Hegel attempted to unify the human and the natural sciences (the Geistes- and the Naturwissenschaften). 