The _Discourses on Livy’s Decades_ occupy a middle position between political and historical science. They are entirely grounded on the study of Livy; but their main importance consists not in the commentary upon the transactions Livy has related, but in the application of these to the general principles of politics and to the circumstances of the writer’s own country. They may be defined as in some sort the _Prince_ rewritten on a larger scale, and copiously illustrated by historical examples; but the effect is much more pleasing. In the other book Machiavelli appears as the mere scientific analyst of politics, and his real purpose might be reasonably questioned; but the _Discourses_ leave no doubt of his genuine patriotism and of his preference of morality to obliquity, except where, as it seems to him, the interest of the state interferes. The problem of the permissibility of an act reprehensible in the abstract, but required by the safety of the stale--as, for example, Mohammed Ali’s massacre of the Mamelukes--is a very difficult one, and Machiavelli cannot be fairly judged from the standpoint of the nineteenth century. He had not seen the trial and failure of his ideal prince on a colossal scale in the person of Napoleon. It was a cardinal error of his to deny a capacity of improvement to human nature and to assume that mankind would be essentially the same in all ages. We see, on the contrary, that the general standard of righteousness has been greatly raised since his time; and that, even if this were not so, the conditions of modern society are adverse to Machiavellian policy: to import this perception, however, into the criticism of his work would be but to reverse his own mistake. Many other criticisms might be addressed to him: he did not, for example, foresee that another set of patriots, from their own point of view, might arise, whose conception of the _summum bonum_ in polity would be entirely different from his own; and that within a few years his maxims might serve as an arsenal for the Jesuits, whose objects would have been his utter abomination. With all his faults and oversights, nothing can deprive Machiavelli of the glory of having been the modern Aristotle in politics, the first, or at least the first considerable writer who derived a practical philosophy from history, and exalted statecraft into science.