Now we must briefly indicate, first, how it happened that this apparently obvious fact—that truth is patterned on knowledge qua intuition—is connected with some specific and very basic issues, and, second, how the outcome of our discussion of intuition-truth and the related problems leads us to a central question of philosophy and indeed of the whole philosophical tradition.
First of all, let us document the importance of Husserl’s basic understanding of the concept of intuition by citing his formulation of “the principle of all principles” (formulated for knowledge in general and for research). Husserl says:
No conceivable theory can mislead us regarding the principle of all prin-ciples: that every originarily presentative intuition [Anschauung] is a legiti-mating source of cognition, that everything that is offered originarily (in its reality “in person,” so to speak) in “intuition” [»Intuition«] is to be sim-ply accepted as that as which it is given, but also only within the limits in which it is given there. (Ideas I, 1913, §24)90
Thus the origin of any research at all and of all knowledge is intuition as the primary source of legitimacy. It was in reference to intuition that Husserl formulated the “principle of all principles” of research. At §136 of Ideas I, Husserl says that “The First Fundamental Form of Rational Consciousness [is] Originarily Presentative ‘Seeing’,”91 i.e., intuition that presents the subject matter “in person.” Husserl puts the word “seeing” in quotes here because he meant the word in a fundamentally broad sense, and not as limited to visual sight.
Likewise, we can understand Kant’s Critique of Pure Reason—or better, all of his philosophizing—only when we see and hold firm to the fact that for Kant authentic knowledge is intuition. [115] In a certain sense, Kant formulates the idea of intuition (intuitus) in even more extreme terms [than Husserl,] and his formulation brings to light the connection with the Greeks.
In his famous letter of 21 February 1772, to Marcus Herz, in which he established the problem of the Critique of Pure Reason—or better, of his whole philosophy—Kant poses the question: “What is the basis on which rests the relation of what in us we call representation [Vorstellung],
90. [Edmund Husserl, Ideen zu einer reinen Phänomenologie und phänomenologischen Philosophie, I. Buch: Allgemeine Einführung in die reine Phänomenologie (Halle: Max Niemeyer, 1913), §24, p. 43; corrected edition in Husserliana III/1, ed. Karl Schuhmann (The Hague: Martinus Nijhoff, 1976). The translation here is adapted from Edmund Husserl, Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy. First Book: General Introduction to a Pure Phenomenology, trans. Fred Kersten (The Hague: Martinus Nijhoff, 1982), p. 44.]
91. [Heidegger here cites the title of §136 of Ideen I (1913), p. 282 / tr. 326.]