 The last area of metaphysics under attack, then, is Rational Theology. Kant’s criticism of rational theology is complicated by his desire to elucidate the sources of the dialectical errors, which he will expose in relation to the specific arguments for God’s existence. (“…Merely to describe the procedure of our reason and its dialectic does not suffice; we must also endeavor to discover the sources of this dialectic, that we may explain…the illusion to which it has given rise” (A581/B607).) Kant thus spends a considerable amount of time tracing the idea of God back to its rational, speculative, sources. According to Kant, “….the Ideal …is based on a natural, not a merely arbitrary idea” (A581/B607). On this score, Kant wants to tell us that we are compelled to think the idea of God (the ens realissimum) when pursuing certain speculative or philosophical interests. More specifically, the idea of a supremely real being (the ens realissimum) is one to which we are inevitably led during our attempts to account for the pure possibility of things in general. The upshot that the idea of the ens realissimum is not an arbitrary or easily dispensable one. Instead, Kant suggests that reason is philosophically constrained to move to such an idea in its efforts to thoroughly determine every thing. Such efforts require thinking the totality, or “All” of reality (the omnitudo realitatis). Such an idea is philosophically required because, in our efforts to thoroughly determine each thing (to know it completely, specify it exhaustively), we must be able to say, of every possible predicate and its contradictory (p v ˜p) which of the two holds of the thing in question. (For every object, it is either A or not A, either B or not B, etc., and this process is iterated until each predicate pair (each positive reality) is exhausted — Kant clearly has a Leibnizian procedure of complete determination in mind here.) This process is parasitic upon the idea of “sum total of all predicates of things in general.” Or, put in another way, we represent “every thing as deriving its own possibility from the share it has in the whole of possibility” (A572/B600). Such an idea, the All of reality, however, defines itself as an individual thing, and leads us to the representation of the “supremely real being.” The problem seems to come in, according to Kant, when the “All” of reality gets hypostatized, and (eventually) personified, thus yielding the ens realissimum (cf. A583/B611n). Here again, Kant thinks that this idea itself gets transmuted into the notion of a given object by virtue of a unique subreption, whereby we dialectically substitute for a principle that is only meant for empirical employment one which holds of things in general. The argument Kant offers is excruciating, but the essential point is that, just as the idea of the soul involved the subreption of the hypostatized consciousness, so too, the idea of the ens realissimum is generated by both a subrepted principle and a hypostatization.