see because we have eyes, but we have eyes because we can "see." But what does it mean to "see"? We understand it, in a very broad sense, as the foundation for all physical, physiological, and aesthetic "optics": namely, it is what allows for an immediate encounter with beings, things, animals, and other people, in the light. Of what help, however, would any light be, no matter how luminous, and what could any optical instrument do, no matter how refined and accommodating, if the power to see did not itself in advance get a being in sight by means of the visual sense and the medium of the light? Just as the eye without the ability to see is nothing, so the ability to see, for its part, remains an "inability" if it does not come into play in an already established relation of man to visible beings. And how could beings be supposed to appear to man, if man did not already relate in his essence to beings as beings? And how could such a relation of man to beings as such hold sway if man did not stand in a relation to Being? If man did not already have Being in view, then he could not even think the nothing, let alone experience beings. And how is man supposed to stand in this relation to Being if Being itself does not address man and claim his essence for the relation to Being? But what else is this relation of Being to the essence of man than the clearing and the open which has lighted itself for the unconcealed? If such clearing did not come into play as the open of Being itself, then a human eye could never become and be what it is, namely the way man looks at the demeanor of the encountering being, the demeanor as a look in which the being is revealed. Since the primordial essence of truth is "unconcealedness" (ἀ-λήθεια), and since ἀλήθεια is already in the concealed the open and the self-luminous, therefore the clearing and its transparency can altogether appear in the form of the lighting of brightness and of its transparency. Only because the essence of Being is ἀλήθεια can the light of the lighting achieve a priority That is why the emergence into the open has the character of shining and appearing. And that is why the perception of what emerges and is unconcealed is a perception of something shining in the light, i.e., it is seeing and looking. Only because looking is claimed in this way can the "eye" receive a priority. It is not because the eye is "sun-like," but it is because the sun as what is radiant itself is of the light and is of the essence of ἀλήθεια, that the eye of man can "look" and can become a sign for the relation of man to the unconcealed in general. Because the essence of truth and of Being is ἀλήθεια, the open, the Greeks could use the eye to characterize the essential relation of man to beings (i.e., ψυχή, the soul) and could speak of the ὄμμα τῆς ψυχῆς, the "eye of the soul."
The Greeks also speak of a conversation of "the soul" with itself (λόγος), and the essence of man would consist in the λόγον ἔχειν. If,