The political maxims of the republic, for the most part, rejected the ancient system of devastating a vanquished state by an instant, unsparing, and crushing plunder, which may answer very well where the tenure is expected to be brief, but does not accord with the formula subdue, retain, advance. Yet depopulation was the necessary incident. Italy, Sicily, Asia Minor, Gaul, Germany, were full of people, but they greatly diminished under Roman occupation. Her maxims were capable of being realized with facility through her military organization, particularly that of the legion. In some nations colonies are founded for commercial purposes, in others for getting rid of an excess of population: the Roman colony implies the idea of a garrison and an active military intent. Each legion was, in fact, so constructed as to be a small but complete army. In whatever country it might be encamped, it was in quick communication with the head-quarters at Rome; and this not metaphorically, but materially, as was shown by the building of the necessary military roads. The idea of permanent occupation, which was thus implied, did not admit the expediency of devastating a country, but, on the contrary, led to the encouragement of provincial prosperity, because the greater the riches the greater the capacity for taxation. Such principles were in harmony with the conditions of solidity and security of the Roman power, which proverbially had not risen in a single day--was not the creation of a single fortunate soldier, but represented the settled policy of many centuries. In the act of conquest Rome was inhuman; she tried to strike a blow that there would never be any occasion to repeat; no one was spared who by possibility might inconvenience her; but, the catastrophe once over, as a general thing, the vanquished had no occasion to complain of her rule. Of course, in the shadow of public justice, private wrong and oppression were often concealed. Through injustice and extortion, her officers accumulated enormous fortunes, which have never since been equalled in Europe. Sometimes the like occurred in times of public violence; thus Brutus made Asia Minor pay five years' tribute at once, and shortly after Antony compelled it to do it again. The extent to which recognized and legitimate exactions were carried is shown by the fact that upon the institution of the empire the annual revenues were about forty millions of pounds sterling. [Sidenote: Value of gold and silver.] The comparative value of metals in Rome is a significant political indication. Bullion rapidly increased in amount during the Carthaginian wars. At the opening of the first Punic War silver and copper were as 1 to 960; at the second Punic War the ratio had fallen, and was 1 to 160; soon after there was another fall, and it became 1 to 128. The republic debased the coinage by reducing its weight, the empire by alloying it. [Sidenote: Connexion between debasement of coinage and political decline.]