The passage comes from Medieval Europe by Chris Wickham.
Peasants do not appear on every page of this book, by any means; but almost everything which does was paid for by the surplus which they handed over, more or less unwillingly, in rent, and it is a mistake to forget it.
I'd like to ask the voice of 'does' in this sentence. My sense of the English grammar makes me wonder if 'does' should not be 'is done'. Of course, since its source is from the published book, it is not likely that this word is actually not proper.
But I have two question on the usage of 'does'.
Frist, doesn't 'is done' also make sense in the context?
Last, what logic of the grammar makes 'does' possible and, if you can, can you show another example of this usage?