Abstract

The paper deals with the concept of ‘reality’ in Kant’s early writings, especially in his Latin dissertation A new Elucidation of the First Principles of Metaphysical Cognition, in The Only Possible Argument in Support of a Demonstration of the Existence of God, and in his Attempt to Introduce the Concept of Negative Magnitude in Philosophy. ‘Reality’ is considered in the two parts of the paper as a concept of ontology and as a concept of natural philosophy, respectively. I argue that Kant’s definition of reality is based on his peculiar demonstration of the principle of sufficient reason and the related theory of ‘internal possibility of things’. Moreover, I argue that these ontological tenets are consistent with Kant’s concept of physical reality and his early acceptance of Newton’s third Law of motion. Aim of my analysis is to show how a unified theory of reality allows Kant to formulate in a new way a grounding principle of cosmology, i.e. the principle of conservation.