This book reconsiders the central epistemological problem since Descartes: the relationship of Mind/World. This is done not through the direct examination of rationality but through an analysis of the concept of objectivity. The development of the idea of objective knowledge is traced from the Presocratics to its effective culmination in Renaissance Science. The argument is that history shows that the acceptance of either a foundational or criteriological theory of truth is not a condition for the occurrence of progressive knowledge. The book concludes with the argument that the apparatus for objective judgment might further, with suitable modification, be transferred to problem areas outside of the empirical investigation of the Physical and Social Sciences.