Unsere Kunst ist ein von der Wahrheit Geblendet-Sein: Das Licht auf dem zurückweichenden Fratzengesicht ist wahr, sonst nichts.
Our art is a way of being dazzled by truth: the light on the grotesquely grimacing retreating face is true, and nothing else. [Kaiser/Wilkins]
Our art is an art that is dazzled by truth: the light shed on the rapidly fleeing grimace is true -- nothing else is. [Hofmann]
Only the light is true; the grimace or face are not, and perhaps neither is its yielding or backward motion. It's interesting that both translators feel the need to insert an adverb of their own before zurückweichenden, which means to yield backwards or behind. Kafka directly invokes neither rapidity or grotesqueness. By choosing to emphasize the grimace itself, Hofmann discards the face, -gesicht, which makes it. The light shed on the grimace itself might be, at least, the registration of some suffering, if we include in suffering other such negative possibilities as disgust or anger. Whereas, the idea here seems to be that the face itself is yielding as it grimaces, being drawn away from the hypothetical witness, not so obviously in flight, but only going back. What I see as I read this is the grimacing face retreating without turning away, whereas, with a rapidly fleeting grimace it is the expression that moves across the stationary face.
Is this light on the grimacing face the same dazzling light mentioned in the first half of the aphorism, or is it a contrast? We in our art, or skillfulness, are only good at dazzling ourselves with a truth whose light we can't really see by, and so it is all too much like blindness. The real light is a faint light that only momentarily illuminates an expression of pain or rejection, which, as it pulls away from us, denies us any opportunity to address it or otherwise enter into some exchange with it. Perhaps it retreats not from the witness but from the light; this could mean that the truth is that disappointment or unpleasantness of reality -- not viciousness, just nastiness -- which comes out when you look for it. There may be here a tacit criticism of the sort of art that ostentatiously aims at the heights, instead of more humbly, but perhaps on the other hand more arrogantly, probes the depths.
Truth is supposed to grant sight, not deprive or injure sight, and the analogy to light is made plain in the second half -- our skill is to be blinded by truth, perhaps to show truth in all its brilliance even as it overwhelms us and therefore cannot be fully seen, or seen at all -- there is another analogy, between truth as blinding light and law as the open but impassible door.