Almost nothing that goes by the name of Historic Rights or Historic Wrongs can be called a truly objective view of the past. Take, for example, the Franco-German debate about Alsace-Lorraine. It all depends on the original date you select. If you start with the Rauraci and Sequani, the lands are historically part of Ancient Gaul. If you prefer Henry I, they are historically a German territory; if you take 1273 they belong to the House of Austria; if you take 1648 and the Peace of Westphalia, most of them are French; if you take Louis XIV and the year 1688 they are almost all French. If you are using the argument from history you are fairly certain to select those dates in the past which support your view of what should be done now.
Arguments about "races" and nationalities often betray the same arbitrary view of time. During the war, under the influence of powerful feeling, the difference between "Teutons" on the one hand, and "Anglo-Saxons" and French on the other, was popularly believed to be an eternal difference. They had always been opposing races. Yet a generation ago, historians, like Freeman, were emphasizing the common Teutonic origin of the West European peoples, and ethnologists would certainly insist that the Germans, English, and the greater part of the French are branches of what was once a common stock. The general rule is: if you like a people to-day you come down the branches to the trunk; if you dislike them you insist that the separate branches are separate trunks. In one case you fix your attention on the period before they were distinguishable; in the other on the period after which they became distinct. And the view which fits the mood is taken as the "truth."
An amiable variation is the family tree. Usually one couple are appointed the original ancestors, if possible, a couple associated with an honorific