"The Determinate World" offers a comprehensive analysis of Hermann von Helmholtz's epistemological approaches to geometry. The author, David Hyder, examines Helmholtz's philosophical arguments, particularly in relation to his work "Conservation of Force." Hyder argues that Helmholtz viewed physical theories as constrained by a regulative ideal aimed at making nature fully comprehensible. This leads to the conviction that all physical quantities must be interpreted as relations between empirically given phenomena. Hyder highlights how Helmholtz conceived geometry in this context by drawing on his research in color theory. This new perspective challenges the prevailing interpretation of Helmholtz's work and provides deeper insights into the empirical nature of geometry and the requirements for a closed system of natural sciences.