But what is the “self-evident pre-philosophical basis” for understanding what ἀλήϑεια means? Heidegger finds within the root of the word ἀλήϑεια an implicit negative sense (-λήϑ-) that is related to the verbs λήϑω/λήϑομαι and λανϑάνω, “to escape notice, to remain hidden.”23 When that negative element is canceled out by the addition of an alpha-privative (ἀ-), the word ἀ-λήϑ-εια conveys to Heidegger a double negative sense: a thing’s condition of “no longer going unnoticed”—or to state it positively: a thing’s having become noticed. For Heidegger, the verb ἀληϑεύειν means “to bring something to light, to bring into our vision something that heretofore was not seen at all.”24 In short, for the Greeks ἀλήϑεια was the condition of a thing insofar as it is now present-and-visible, and not just spatio-temporally present to one’s eyes but meaningfully present to one’s mind.
We can confirm this reading indirectly in the texts of Aristotle when he speaks of friendship in Nicomachean Ethics. One can feel goodwill (εὔνοια) for another person, he says, but that does not constitute friendship unless and until the goodwill is reciprocated, and not only reciprocated but also mutually recognized. The Greek verb Aristotle uses here for “to recognize” is μὴ λανϑάνω (“not” + “to be hidden, unnoticed”), hence, to be not-hidden—or, in a word: noticed or known.25 The same Greek usage continues some seven centuries later in Plotinus.26 He defines sensation (τὸ αἰσθάνεσθαι) as “being aware of what affects you.” But the Greek expression for such awareness is τὸ τὸ πάϑος μὴ λανϑάνειν—“to have what affects you not be hidden from you” (again, a double negative). Moreover, later in that text Plotinus places μὴ λανϑάνειν, “to not be hidden.” in apposition to the (late Greek) verb γινώσκω, “to know.” Given such examples, the “‘self-evident’ pre-philosophical basis” of the ancient Greek understanding of ἀλήϑεια is a thing’s condition of being open and available for knowledge, whether theoretical or practical.
23. GA 54: 61.30–31 = 42.7–8: λανϑάνει: “unbemerkt.” See Wilhelm Luther, “Wahrheit” und “Lüge” im ältesten Griechentum, 11–13: unbemerkt; hence verborgen, verdeckt, verhüllt; Unverborgenheit. Also Robert Beekes, with Lucien van Beek, Etymological Dictionary of Greek, I, 65f., s.v. ἀληϑής.
24. GA 45: 94.9–10 = 83.38–39: “Hervor-bringen heißt hier Ans-Licht-bringen, etwas bisher überhaupt noch nicht Gesichtetes zu Gesicht bringen.”
25. Nicomachean Ethics VIII 2, 1155b34: μὴ λανϑάνουσαν: when the goodwill is “not hidden” (in Bekker’s Latin, “non occultam neque incognitam.” III: 574a11) and 1156a4: μὴ λανϑάνοντας: the mutual goodwill and benevolence must “not be hidden”—that is, must be recognized (“cognitum,” Bekker, III: 574a19). See also Physics III 1, 200b13–14: If we are to understand ϕύσις, the meaning of κίνησις must “not be hidden.” μὴ λανϑάνειν (Bekker: “non lateat nos.” III: 110b29), which Aristotle couples with ἀγνοεῖσϑαι, “to not know, to be ignorant of.” Cf. Aquinas: Commentaria in octo libros Physicorum, liber III, lectio 1, no. 279: “ignorato motu, ignoratur natura.”
26. Plotinus, Enneads I 4: 2.3–6.