If anything has demonstrated the fact that Causality has nothing to do with history, it is the familiar “decline” of the Classical, which accomplished itself long before the irruption of Germanic migrants.[154] The Imperium enjoyed the completest peace; it was rich and highly developed; it was well organized; and it possessed in its emperors from Nerva to Marcus Aurelius a series of rulers such as the Cæsarism of no other Civilization can show. And yet the population dwindled, quickly and wholesale. The desperate marriage-and-children laws of Augustus--amongst them the _Lex de maritandis ordinibus_, which dismayed Roman society more than the destruction of Varus’s legions--the wholesale adoptions, the incessant plantation of soldiers of barbarian origin to fill the depleted country-side, the immense food-charities of Nerva and Trajan for the children of poor parents--nothing availed to check the process. Italy, then North Africa and Gaul, and finally Spain, which under the early Cæsars had been one of the most densely populated parts of the Empire, become empty and desolate. The famous saying of Pliny--so often and so significantly quoted to-day in connexion with national economics--“_Latifundia perdidere Italiam, jam, vero et provincias_,”[155] inverts the order of the process; the large estates would never have got to this point if the peasantry had not already been sucked into the towns and, if not openly, at any rate inwardly, surrendered their soil. The terrible truth came out at last in the edict of Pertinax, A.D. 193, by which anyone in Italy or the provinces was permitted to take possession of untended land, and if he brought it under cultivation, to hold it as his legal property. The historical student has only to turn his attention seriously to other Civilizations to find the same phenomenon everywhere. Depopulation can be distinctly traced in the background of the Egyptian New Empire, especially from the XIX dynasty onwards. Street widths like those to Amenophis IV at Tell-el-Amarna--of fifty yards--would have been unthinkable with the denser population of the old days. The onset of the “Sea-peoples,” too, was only barely repulsed--their chances of obtaining possession of the realm were certainly not less promising than those of the Germans of the fourth century _vis-à-vis_ the Roman world. And finally the incessant infiltration of Libyans into the Delta culminated when one of their leaders seized the power, in 945 B.C.--precisely as Odoacer seized it in A.D. 476. But the same tendency can be felt in the history of political Buddhism after the Cæsar Asoka.[156] If the Maya population literally vanished within a very short time after the Spanish conquest, and their great empty cities were reabsorbed by the jungle, this does not prove merely the brutality of the conqueror--which in this regard would have been helpless before the self-renewing power of a young and fruitful Culture-mankind--but an extinction from within