Primo Levi wrote in If This Is A Man on being good:

However little sense there may be in trying to specify why I, rather than thousands of others, managed to survive the test, I believe that it was really due to Lorenzo that I am alive today; and not so much for his material aid, as for his having constantly reminded me by his presence, by his natural and plain manner of being good, that there still existed a just world outside our own, something and someone still pure and whole, not corrupt, not savage, extraneous to hatred and terror; something difficult to define, a remote possibility of good, but for which it was worth surviving.

The personages in these pages are not men. Their humanity is buried, or they themselves have buried it, under an offence received or inflicted on someone else. The evil and insane SS men, the Kapos, the politicals, the criminals, the prominents, great and small, down to the indifferent slave Häftlinge, all the grades of the mad hierarchy created by the Germans paradoxically fraternized in a uniform internal desolation.

But Lorenzo was a man; his humanity was pure and uncontaminated, he was outside this world of negation. Thanks to Lorenzo, I managed not to forget that I myself was a man.