Abstract
Readers of Descartes, Kant and Hegel are often mystified by the central epistemological and ontological concepts, purposes, strategies and assumptions of these three systems. The aim of this work is to clarify the linkages between the foundational and metaphysical transformations that are developed by each thinker and the problems of science and human liberation. Cristaudo's survey brings to the centre of the discussion, ideas which are often neglected or marginalised by philosophers - the this-worldly purpose of Descartes' metaphysics, the significance of Kant's metaphysical dualism and the Fichtean and Schellingean roots of Hegel's absolute idealism.