 Idealism in sense (1) has been called “metaphysical” or “ontological idealism”, while idealism in sense (2) has been called “formal” or “epistemological idealism”. The modern paradigm of idealism in sense (1) might be considered to be George Berkeley’s “immaterialism”, according to which all that exists are ideas and the minds, less than divine or divine, that have them. (Berkeley himself did not use the term “idealism”.) The fountainhead for idealism in sense (2) might be the position that Immanuel Kant asserted (if not clearly in the first edition of his Critique of Pure Reason (1781) then in his Prolegomena to Any Future Metaphysics (1783) and in the “Refutation of Idealism” in the second edition of the Critique) according to which idealism does “not concern the existence of things”, but asserts only that our “modes of representation” of them, above all space and time, are not “determinations that belong to things in themselves” but features of our own minds. Kant called his position “transcendental” and “critical” idealism, and it has also been called “formal” idealism. However, Kant’s position does not provide a clear model of idealism at all. While Kant himself claimed that his position combined “empirical realism” with “transcendental idealism”, that is, combined realism about external, spatio-temporal objects in ordinary life and science with the denial of the reality of space and time at the level of things as they are in themselves, it also insisted upon the reality of things as they are in themselves existing independently from our representations of them, thus denying their reducibility to representations or the minds that have them. In this way, Kant’s position actually combines the transcendental ideality of space and time with a kind of realism about the existence of things other than minds. 