From David Winters, "Vanishing acts" [review of Cathy Caruth, Literature in the Ashes of History], The Times Literary Supplement (November 14, 2014), p. 26:
So, trauma conveys a kind of philosophical force: it puts pressure on the epistemological status -- and the evidential value -- of recollected and recounted memories. Crucially though, for Caruth, this pressure is not only epistemological; it is also necessarily ethical. As before, this is because trauma cuts across the personal and the historical. Trauma is "not so much a symptom of the unconscious as a symptom of history", such that "the traumatized carry an impossible history within them". For Caruth, it follows that this "impossible" quality must be preserved -- particularly if we wish to "bear witness" to the histories that our taumas transmit. Once more, it is easy to see this idea's deconstructive colouring. Caruth's argument that trauma's aporia ought to be retained recalls Derrida's similar style of ethical thought.