111. The "apriori" and φύσις
i.e., τὸ πρότερον τῇ φύσει ["what is first by nature"]. φύσις the paradigm and the "earlier than," descent, origin.
The earliest, the first to come to presence, the presencing is φύσις itself, though, in unity with ἀλήθεια, immediately covered over by the ἰδέα.
How does such a question of the πρότερον arise? On the basis of the ἰδέα as the ὄντως ὄν.
The earliest in the essential occurrence is the essential occurrence itself as that of beyng.
Apriori—from what goes before; the apriori only where the guiding question, metaphysics.
In the transition, however, only apparently is the "apriori" still a "problem": conceived in terms of the event, the relation between beyng and beings is quite different.
112. The "apriori"
The apriori in the proper sense only where ἰδέα, which means that beingness (κοινόν) as the ὄντως ὄν is more eminently and thereby is in the first place a being [seiend].
The apriori, in accord with the way Plato introduced it, will in the future always mean for metaphysics that beingness comes before beings.
In company with the ἰδέα, the apriori becomes the perceptio; i.e., the apriori is assigned to the ego percipio and thus to the "subject." In other words, representing is now what comes before.
The "understanding of being," as determined in Being and Time, appeared to be merely an extension of this representing that comes before, and yet (understanding as pro-jection-Da-sein) it is completely different; as transition, however, it does point back into metaphysics. The truth of beyng and the essential occurrence of beyng are neither what comes earlier nor what comes later.
Da-sein is the Simultaneity of time-space with what is true as a being, and it essentially occurs as the grounding ground, as the "between" and "middle" of beings themselves