We need not consider curiously whether things would or will happen in exactly this way: the actual presumption is that before coal is exhausted the whole social structure will be modified; and it is conceivable that the idle class may have been eliminated. But we are supposing a less progressive evolution for illustration's sake. Suffice it that such a development would be in a measure economically analogous to what took place in ancient Rome. If the upper-class population of such a hypothetical future in England, instead of receiving only dividends from foreign stocks and pensions from the revenue of India, were able to extort an absolute tribute from India and other dominions, the parallel would be so much the closer. What held together the Roman Empire so long was, on the one hand, the developed military and juridical organisation with its maintaining revenue, and on the other hand the absence of any competent antagonist. Could a Mithridates or an Alexander have arisen during the reign of one of the worse emperors, he might more easily have overrun the Roman world than Rome did Carthage. As it was, all the civilised parts of the Empire shared its political anæmia; and indeed the comparative comfort of the Roman peace, with all its burden of taxation, was in many of the provinces a sufficient though precarious ground for not returning to the old life of chronic warfare, at least for men who had lost the spirit of reasoned political self-assertion. Under good emperors, the system worked imposingly enough; and Mommsen, echoing Gibbon, not unwarrantably bids us ask ourselves whether the south of Europe has ever since been better governed than it was under the Antonines.[206] The purely piratical plunder carried on by governors under the Republic was now, no doubt, in large measure restricted. But, to say nothing of the state of character and intellect, the economic evisceration was proceeding steadily alike under good emperors and bad, and the Stoic jurists did but frame good laws for a worm-eaten society. So long as the seat of empire remained at Rome, drawing the tribute thither, the imperial system would give an air of solidity to Italian life; but when the Roman population itself grew cosmopolitanised in all its classes, taking in all the races of the Empire, the provinces were in the terms of the case as Roman as the capital; and there was no special reason, save the principle of concentration, why the later emperors should reside there. Where of old the provincial governors had extorted from their subjects fortunes for themselves, to be spent in Rome like the public tribute, they would now tend to act as permanent dwellers in their districts.[207] Once the palace was set up elsewhere, the accessories of administration inevitably followed; and the transference of official and other population would partly balance the restriction of food supply caused by the deflection of Egyptian