Not only does Renouvier thus declare the Middle Ages to be a regress, but he goes the length of asserting that the development of European history _could_ have been different. This is his doctrine of freedom applied to history. There is no reason at all for our regarding the Middle Ages or any such period as necessitated in the order of mankind’s development. There is no law governing that development; consequently, had mankind, or even a few of its number, willed and acted upon their freedom differently, the whole trend of the period we call the Dark Ages might have been quite other than it was. Renouvier does not shirk the development of this point, which is a central one for his purpose. It may seem fantastic to the historians, who must of course accept the past as given and consequently regard reflection on “what might have been” as wasted time. Certainly the past cannot be altered—that is not Renouvier’s point. He intends to give a lesson to humanity, a stern lesson to cure it of its belief in fatalism in regard to history. This is the whole purpose of the curious volume he published in 1876, entitled _Uchronie_, which had as its explanatory sub-title _L’Utopie dans l’Histoire, Esquisse historique du Développement de la Civilisation européenne, tel qu’il n’a pas été, tel qu’il avail pu être_. The book, consisting of two manuscripts supposed to be kept in the care of an old Dutch monk, is actually an imaginary construction by Renouvier himself of European history in the period 100 to 800 A.D., written to show the real possibility that the sequence of events from the Emperor Nerva to the Emperor Charlemagne might have been radically different from what it actually was.