some answers I think are interesting:
The very ink with which all history is written is merely fluid prejudice. ~Mark Twain, Following the Equator
It might be a good idea if the various countries of the world would occasionally swap history books, just to see what other people are doing with the same set of facts. ~Bill Vaughan
The past actually happened but history is only what someone wrote down. ~A. Whitney Brown, The Big Picture
History is a pack of lies about events that never happened told by people who weren't there. ~George Santayana
Man is an historical animal, with a deep sense of his own past; and if he cannot integrate the past by a history explicit and true, he will integrate it by a history implicit and false. ~Geoffrey Barraclough, History in a Changing World
The idea of history in any age, like the idea of property, or of progress, is an unstable compound; it is put together as needed, by historians or by philosophers, out of the irreconcilable opinions of men. ~F. Smith Fussner, The Historical Revolution
Delusion about history is a serious matter; it can gravely affect the history that is waiting to be made. ~John Terraine
History supplies little beyond a list of those who have accommodated themselves with the property of others. ~Voltaire, Philosophical Dictionary
The real history does not get written, because it is not in people's brains but in their nerves and vitals. ~Alfred North Whitehead, Dialogues of Alfred North Whitehead
The "argument without end":
To expect from history those final conclusions which may perhaps be obtained in other disciplines is in my opinion to misunderstand its nature… The scientific method serves above all to establish facts; there is a great deal about which we can reach agreement by its use. But as soon as there is a question of explanation, of interpretation, of appreciation, though the special method of the historian reamins valuable, the personal element can no longer be ruled out, that point of view which is determined by the circumstances of his time and by his own preconceptions…. we cannot see the past in a single communicable picture except from a point of view, which implies a choice, a personal perspective. It is impossible that two historians, especially two historians living in different periods, should see any historical personality in the same light… A man’s judgement - for however solemnly some people may talk about the lessons of History, the historian is after all only a man sitting at his desk - a historian’s judgement, then, may seem to him the only possible conclusion to draw from the facts, he may feel himself sustained and comforted by his sense of kinship with the past, and yet that judgement will have no finality. Its truth will be relative, it will be partial…The study even of contradictory conceptions can be frutiful. Any one thesis or presentation may in itself be unacceptable, and yet, when it has been jettisoned, there remains something of value. Its very critics are that much richer. History is indeed an argument without end.
(from historian Pieter Geyl's book "Napoleon: for and against")