Rome may have understood the principles of commerce imperfectly in the third century and not perfectly in the twentieth; but that does not save her citizens from experiencing their applications. Signor Mussolini might peruse with interest the annals of Aurelian, who, “ignorant or impatient of the restraints of civil institutions,” fell by the hand of an assassin within a year of his deflation of the currency, “regretted by the army, detested by the Senate, but universally acknowledged as a warlike and fortunate prince, the useful though severe reformer of a degenerate State.” Ricardo, speaking in the House of Commons on the 12th of June 1822,[44] gave his opinion that: “If in the year 1819 the value of the currency had stood at 14s. for the pound note, which was the case in the year 1813, he should have thought that, on a balance of all the advantages and disadvantages of the case, it would have been as well to fix the currency at the then value, according to which most of the existing contracts had been made; but when the currency was within 5 per cent of its par value, he thought they had made the best selection in recurring to the old standard.” [44] The great debate of June 11 and 12, 1822, on Mr. Western’s Motion concerning the Resumption of Cash Payments, well illustrates, more particularly in the speeches of the opener, Mr. Western, and of the opposer, Mr. Huskisson, the regularity of the evils which follow a deflationary raising of the standard, and the unchanging antithesis between the temperaments of deflationists and devaluers, though I doubt if any present-day deflationists could make a speech at the same time so able and so unfair as Mr. Huskisson’s. The same is repeated in his _Protection to Agriculture_[45] where he approves the restoration of the old standard when gold was £4 : 2s. per standard ounce, but adds that, if it had been £5 : 10s., “no measure could have been more inexpedient than to make so violent a change in all subsisting engagements.” [45] Works, p. 468. II. _Stability of Prices_ versus _Stability of Exchange_. Since, subject to the qualification of Chapter III., the rate of exchange of a country’s currency with the currency of the rest of the world (assuming for the sake of simplicity that there is only one external currency) depends on the relation between the internal price level and the external price level, it follows that the exchange cannot be stable unless _both_ internal _and_ external price levels remain stable. If, therefore, the external price level lies outside our control, we must submit either to our own internal price level or to our exchange being pulled about by external influences. If the external price level is unstable, we cannot keep _both_ our own price level _and_ our exchanges stable. And we are compelled to choose.