ABSTRACT
The ontological proof, as Immanuel Kant sets it forth, defines God as the ens realissimum, the most real being; i.e. the subject of all predicates that belong to being absolutely. The practical use of reason is developed briefly near the end of The Critique of Pure Reason, and more fully in The Critique of Practical Reason. He proposes to make a critical examination of the theoretical doctrine. To explain Kant's theory of space and time clearly is not easy, because the theory itself is not clear. There is as throughout Kant's theory of the subjectivity of space and time, a difficulty which he seems to have never felt. The metaphysical argument is chiefly concerned to prove that space is an intuition, not a concept. The 'thing-in-itself' was an awkward element in Kant's philosophy, and was abandoned by his immediate successors, who accordingly fell into something very like solipsism. The important development from Kant's philosophy was that of Hegel.
