Table of Contents

I. On the Origin and Significance of the Axioms of Geometry.- Notes [M.S.].- II. On the Facts Underlying Geometry.- Notes [P.H.].- III. Numbering and Measuring from an Epistemological Viewpoint.- Notes [P.H.].- IV. The Facts in Perception.- Appendix 1.- Appendix 2.- Appendix 3.- Notes [M.S.].- A. Works by Helmholtz.- B. Biographical Materials.- C. Works on Helmholtz.- D. Index to Cited Works (with English translation where known).- Index of Names.