This book offers a new interpretation of Hermann von Helmholtz's work on the epistemology of
geometry. A detailed analysis of the philosophical arguments of Helmholtz's Erhaltung der Kraft
shows that he took physical theories to be constrained by a regulative ideal. They must render
nature completely comprehensible which implies that all physical magnitudes must be relations
among empirically given phenomena. This conviction eventually forced Helmholtz to explain how
geometry itself could be so construed. Hyder shows how Helmholtz answered this question by
drawing on the theory of magnitudes developed in his research on the colour-space. He argues
against the dominant interpretation of Helmholtz's work by suggesting that for the latter it
is less the inductive character of geometry that makes it empirical and rather the regulative
requirement that the system of natural science be empirically closed.
