 Schlick and Paul Hertz assess the relevance of Helmholtz’s work as follows: Helmholtz’s “classic works on physics — one may for example recall the energy principle or his work on vortex motions — stand at the end of lines of development….his work seems for science at its present stage to be something completed and left behind. There is only one field, but a very important one, to which this does not apply: it does not hold for Helmholtz’s epistemological studies” (Hertz and Schlick 1977 [1921], xxxiv). In his Notes on “On the Origin and Significance of the Axioms of Geometry,” Schlick sees the “chief epistemological result” of Helmholtz’s work in the replacement of the Kantian necessary a priori with a judgment that “Euclidean space is not an inescapable form of our faculty of intuition, but a product of experience” (Schlick’s note to Helmholtz 1921 [1868], 35). 