Shaftesbury Avenue Handicap was for many of you until a paragraph ago. How, then, are we to think of my comporting towards my computer as an overcoming of a prior lēthē? The key is that the prior lēthē need not be temporally prior. To say that there is lēthē here is not to say that after I shut my computer down for the night it comes to be in the condition that the Shaftesbury Avenue Handicap was in. Rather, the point is that were it not for my comporting towards it, the entity would remain in the darkness of unintelligibility. When I do comport towards it, I lift it out of this darkness: I un-cover it, make it intelligible.
So, at the second plank, lēthē is an actual or counterfactual unintelligibility that is ontologically and conceptually presupposed by discovering entities as that and what they are. Whether Heidegger is right that discovering entities presupposes this lēthē in these ways is a question for another project. But this is the phenomenon that he is talking about when he says things such as: ‘Truth (uncoveredness) is something that must always first be wrested from entities. Entities get snatched out of their hiddenness [Verborgenheit]. The factical uncoveredness of anything is always, as it were, a kind of robbery’ (SZ: 222).
In addition to overcoming a prior concealment, discovering the entity as that and what it is also simultaneously conceals, in various ways. Heidegger never (as far as I know) discusses what is perhaps the most obvious instance of such concealing: I always discover entities in terms of general standards for counting as that and what they are, and this necessarily obscures entities in their radical particularity. But this point seems trivial. Notice instead that when I comport towards an entity as x, I at the same time conceal it as y (where x and y are contraries of an appropriate sort). There is a certain richness or depth to entities—a range of ways in which they might be meaningful—that is necessarily covered over when an entity shows up as meaningful in some determinate way. Thus if an invitation shows up to me as an unwanted imposition, it is at the same time concealed from me as an exciting opportunity. If something shows up to me as available for use, then it cannot show up to me at the same time as a factical case of Dasein. If a mug shows up as to drink coffee from, then it is at the same time hidden as to be