Full Idea
The writer of history deals not with what really happened but merely with supposed events, for only the latter have had an effect. ...All historians speak of things that have never existed except in imagination.
Gist of Idea
History does not concern what really happened, but supposed events, which have all the influence
Source
Friedrich Nietzsche (Dawn (Daybreak) [1881], 307)
Book Reference
Nietzsche,Friedrich: 'Dawn (Daybreak) (v 5)', ed/tr. Smith, Brittain [Stanford 2011], p.190
A Reaction
This seems blatantly true, and is most obvious in the case of forged documents which have been hugely influential. Erroneous conspiracy theories are another example. (Note: only scorn conspiracy theories if you think conspiracies never happen!).