There is a passage at the very end describing the limits of history, what we can know about the past, and what we will never be able to know, which I thought was expressed very beautifully:
Our document, though in its own way eloquent, is on these subjects mute. We may call Eurydice forth from the world of the dead, but we cannot make her answer; and when we turn to look at her we glimpse her only for a moment, before she slips from our grasp and flees. As all historians know the past is a great darkness, and filled with echoes. Voices may reach us from it; but what they say to us is imbued with the obscurity of the matrix out of which they come; and, try as we may, we cannot always decipher them precisely in the clearer light of our own day.