III. The Interplay [211-213]

11. The foremost subsequent—and more appropriate—version of Platonism (the theory of Ideas as theory of the beingness of beings) is not "idealism," but "realism"; res: the "what," the thing; realitas as whatness, essentia, the genuine medieval "realism"; the universale constitutes the ens qua ens.

12. Through nominalism, however, the "this," the factuality of the individual, becomes the genuine realitas, and realitas is accordingly claimed for the distinguishing characteristic of the individual, for what is immediately present at hand here and now, for existentia. Remarkable: the term "reality" now comes to mean "existence," "actuality," "thereness" ["Existenz," "Wirklichkeit," "Dasein"].

13. For various motives, the individual, the individual soul, the individual human, the "I," is experienced correspondingly as what most eminently is, as the most real being, and only in that way is the ego cogito—ergo sum possible at all. In this assertion, "being" is attributed to the individuum, whereby it is to be noted that the assertion properly refers to the certainty of the mathematical relation between cogitare and esse; the axiom of mathesis.

14. Now no longer does ἰδέα signify the universale as such in the Greek sense of the εἶδος of presencing; it refers instead to the perceptum grasped in the percipere of the ego. It means "perceptio" in the ambiguity of our word "representation" [Vor-stellung]. If ἰδέα is taken so broadly, then even what is individual and changeable is a perceptum. The ἰδέα as perceptum: the idea in its shining back. The ἰδέα as εἶδος: the idea in the shining forth of presencing. It is only the interpretation of ἰδέα as perceptio that turns Platonism into an "idealism": the beingness of beings now becomes representedness, and beings are thought of "idealistically" (esse = verum esse = certum esse = ego percipio, cogito me cogitare). Consequently, in Kant the "ideas" are indeed saved, but only as representations and principles of "reason" qua human reason

From here the step to absolute idealism. Hegel's concept of "ideas" (cf. the following excursus), the absolute self-appearance to itself of the absolute as absolute knowledge. Thereby possible to grasp Plato in a new way and assign Greek philosophy to the phase of immediacy. (Cf. on "idealism": "Übungen, Nietzsches metaphysische Grundstellung: Sein und Schein," summer semester 1937, and on nominalism: "Übungen, Die metaphysischen Grundstellungen des abandländischen Denkens [Metaphysik]," w. s. 1937-38.)

Contributions to Philosophy (of the Event) (GA 65) by Martin Heidegger