There is a further lesson to be learned by us moderns from the history of the decadence of the Roman Empire: and that is, not to mistake the glamour of the external manifestations of wealth and power for signs of real wealth and power. A civilisation is not always in reality richer and stronger in times when it bears the most visible marks of so being; we are rather apt to find that, when it is most dazzling in outward seeming, its decadence has already begun. We often halt in stupefaction and admiration before the great ruins of ancient Rome, especially those offered by the European provinces of the Empire. We think how great, powerful, and rich must have been the Empire which could rear monuments so massive that all the centuries have not been able to sweep them entirely from the face of the earth. And yet, if we are to look at these relics in their right light, we must remember that practically all the great Roman monuments whose remains survive to our day on a large scale, belong to the third, fourth, and fifth centuries of the Christian era—to the centuries of decadence and dissolution. As the Empire weakens and ages, its monuments become more and more elaborate and colossal. A fairly safe rule for guessing the century to which Roman monuments belong is to assume that the more imposing the ruins, the later is the epoch to which they should be attributed. For Rome herself, the time of the greatest expansion, splendour, and population was the middle of the fourth century—that is to say, when her decadence was already far advanced. Not till then did Rome become, for the number and size of her temples, the magnificence of her baths, her basilicas, and her private palaces, for the beauty of her public gardens, for her size and population, the first and most marvellous city of the Empire: the portent which evokes the admiration of the whole world. How much smaller, on the other hand, how much more simple and modest was she in the first century, a time when the Empire really was at its most flourishing epoch, with its frontiers safe, its population on the up-grade, its cities developing themselves by a process of growth which was still a perfectly natural one, agriculture, trade, and industries in a sound condition, and the State well organised and strong.