The Problems With Using History, from Nigel Davies
As an exercise in falsification I suggest looking for all the cases of the wrong lessons that were learned from 'history' which led to disasterous actions. The only problems here are that they won't be too well documented, firstly because people try to hide their mistakes and secondly because a lot of them will have been made by the currently extinct. A good place to start is with fallen empires, all of which will have thought they were acting very reasonably at the time. Similarly great books tend to be viewed as great until they were discovered to be just baloney — for this we need the best seller list of 1600.