Augustine at a time when "idealism" had not yet developed. Idealism only since Descartes.
2. German Idealism, predelineated in Leibniz and based on Kant's transcendental step beyond Descartes, is the idealism that attempts an absolute thinking of the ego cogito of transcendental apperception. At the same time, such idealism grasps the absolute within a directedness toward Christian dogma, in such a way that the latter attains in this philosophy its proper truth that has come back to itself; in Cartesian (!) terms, it attains the highest self-certainty. The error of this German Idealism—if in these domains such a judgment can be made at all—is not that it was too "far from life"; just the opposite: this philosophy moved completely and fully in the domain of modern Dasein and of Christianity, instead of posing beyond "beings" the question of being. German Idealism was too close to life, and in a certain way it itself gave birth to what supplanted it, namely, the non-philosophy of positivism which is now celebrating its biologistic triumphs.
104. German Idealism
Here truth becomes the certainty that develops into an unconditioned trust in spirit and so unfolds for the first time as spirit in its absoluteness. Beings are completely transposed into objectivity, and objectivity is in no way overcome through "sublation"; on the contrary, objectivity extends to the representing I and to the relation of representing the object and representing the representation. Machination as the basic character of beingness now lapses into the form of the subject-object dialectic, which, as absolute, plays out to their end and orders together all possibilities of every known realm of beings. Here once again is sought complete security against all uncertainty, Le., a conclusive grip on the correctness of absolute certainty but also, unwittingly, an evasion of the truth of beyng. No bridge leads from here to the other beginning. Yet it is precisely this thinking of German Idealism that we must know, for it brings the machinational power of beingness into its extreme, unconditioned development (it elevates the conditionedness of the ego cogito into the unconditioned) and prepares the end
Instead of becoming deposited in the banality of immediate evidence, the obviousness of being is now systematically extended to the wealth of the historicality of the spirit and of the forms of the spirit.