Max Horkheimer from Dawn and Decline - as cited in Michael Löwy's Fire Alarm:

When you are at the lowest ebb, exposed to an eternity of torment inflicted upon you by other human beings, you cherish, as a dream of deliverance, the idea that a being will come who will stand in the light and bring truth and justice for you. You do not even need this to happen in this lifetime, nor in the lifetime of those who are torturing you to death, but one day, whenever it comes, all will nonetheless be repaired... It is bitter to be misunderstood and to die in obscurity. It is to the honor of historical research that it projects light into that obscurity.

* this is not in the English Translation of Dawn and Decline.
* I think of this passage often, and was surprised I hadn't posted this already.