FW Maitland makes a counterintuitive point: reading history backwards helps us to discard modern baggage. He is writing about English legal history, but I suppose this can apply elsewhere.
“The task of reconstructing ancient ideas is hazardous, and can only be accomplished little by little. If we are in a hurry to get to the beginning we shall miss the path. Against many kinds of anachronism we now guard ourselves. We are careful of costume, of armour and architecture, of words and forms of speech. But it is far easier to be careful of these things than to prevent the intrusion of untimely ideas. In particular there lies a besetting danger for us in the barbarian’s use of a language which is too good for his thought. Mistakes then are easy, and when committed they will be fatal and fundamental mistakes. If, for example, we introduce the persona ficta too soon, we shall be doing worse than if we armed Hengest and Horsa with machine guns or pictured the Venerable Bede correcting proofs for the press; we shall have built upon a crumbling foundation. The most efficient method of protecting ourselves against such errors is that of reading our history backwards as well as forwards, of making sure of our middle ages before we talk about the ‘archaic’, of accustoming our eyes to the twilight before we go out into the night.”
“The law implied in Domesday Book ought to be for us very difficult law, far more than the law of the thirteenth century, for the thirteenth century is nearer to us than is the eleventh. The grown man will find it easier to think the thoughts of the school-boy than to think the thoughts of the baby. And yet the doctrine that our remote forefathers being simple folk had simple law dies hard. Too often we allow ourselves to suppose that, could we but get back to the beginning, we should find that all was intelligible and should then be able to watch the process whereby simple ideas were smothered under subtleties and technicalities. But it is not so. Simplicity is the outcome of technical subtlety; it is the goal not the starting point. As we go backwards the familiar outlines become blurred; the ideas become fluid, and instead of the simple we find the indefinite. But difficult though our task may be, we must turn to it.”
Reading backwards is implied in the title of the book from which this is taken: Domesday Book and Beyond, Cambridge University Press, 1897.