"BEFORE MACHIAVELLI, princes and conquerors did not hesitate to apply on many occasions bad faith, perfidy, falsehood, cruelty, assassination, every kind of crime of which the flesh and blood man is capable, to the attainment of power and success and to the satisfaction of their greed and ambition. But in so doing they felt guilty, they had a bad conscience to the extent that they had a conscience. Therefore, a specific kind of unconscious and unhappy hypocrisy -- that is, the shame of appearing to oneself such as one is -- a certain amount of self-restraint, and that deep and deeply human uneasiness which we experience in doing what we do not want to do and what is forbidden by a law that we know to be true, prevented the crimes in question from becoming a rule, and provided governed peoples with a limping accommodation between good and evil which, in broad outline, made their oppressed lives, after all, livable.
"After Machiavelli, not only the princes and conquerors of the cinquecento, but the great leaders and makers of modern states and modern history, in employing injustice for establishing order, and every kind of useful evil for satisfying their will to power, will have a clear conscience and feel that they accomplish their duty as political heads. Suppose they are not merely skeptical in moral matters, and have some religious and ethical convictions in connection with man's personal behavior, then they will be obliged, in connection with the field of politics, to put aside these convictions, or to place them in a parenthesis; they will stoically immolate their personal morality on the altar of the political good. What was a simple matter of fact, with all the weaknesses and inconsistencies pertaining, even in the evil, to accidental and contingent things, has become, after Machiavelli, a matter of right, with all the firmness and steadiness proper to necessary things. A plain disregard of good and evil has been considered the rule, not of human morality -- Machiavelli never pretended to be a moral philosopher -- but of human politics.
"For not only do we owe to Machiavelli our having become aware and conscious of the immorality displayed, in fact, by the mass of political men, but by the same stroke he taught us that this very immorality is the very law of politics. Here is that Machiavellian perversion of politics which was linked, in fact, with the Machiavellian prise de conscience of average political behavior in mankind. The historic responsibility of Machiavelli consists in having accepted, recognized, indorsed as normal the fact of political immorality, and in having stated that good politics, politics conformable to its true nature and to its genuine aims, is by essence non-moral politics.
"Machiavelli belongs to that series of minds, and some of them more profound than his, which all through modern times have endeavored to unmask the human being. To have been the first in this lineage is the greatness of this narrow thinker eager to serve the Medici as well as the popular party in Florence, and disappointed on both counts. Yet in unmasking the human being he maimed its very flesh, and wounded its eyes. To have thoroughly rejected ethics, metaphysics and theology from the realm of political knowledge and political prudence is his very own achievement, and it is also the most violent mutilation suffered by the human practical intellect and the organism of practical wisdom."
~Jacques Maritain: The Range of Reason, 11, 1; 'Machiavelli's Machiavellianism'.