> I think the quote you refer to speaks for itself.
With all due respect, you're missing my point. My point is that the quote doesn't speak for itself. It leaves all the really hard questions unanswered.
Here are some of the hard questions that I have in mind:
1) Are any statements concerning history not perspectival? (If so, why and what kind or kinds? If not, wow: not even (putatively) factual statements like 'World War I broke out in the year 1914'?)
2) If historical statements are so deeply perspectival, how do we rank or otherwise evaluate competing statements about history? If we don't rank or evaluate them at all, how do we form coherent sets of beliefs about the past (which many people appear to do)? How do people manage to choose between conflicting claims? How should they choose?
3) Are all statements about history equally valid? If so, does this run the risk of meaning that all statements about history are equally 'invalid'? If not, why not?
4) Are historical statements especially perspectival or are all statements of belief (period) perspectival? If historical statements are especially perspectival, why? If not - if everything anyone states is completely perspectival - wow. Again, that's a big claim.
Yes, my argument used a reductio ad absurdum, but I wan't trying to make your claim absurd. That is, I truly meant to take it seriously: seriously enough to dispute, to ask questions about and to discuss. Saying that all historical claims are perspectival is a big claim. I was genuinely asking you to clarify what you meant.