Answer:
Machiavelli believes power is legitimized by a prince's ability to defend his kingdom from foreign threats and maintain domestic order. Machiavelli is a realist; he asserts that the ends justify the means in terms of keeping his subjects in order, thereby legitimizing his reign. "There are only two things a prince must fear: internal subversion from his subjects; and external aggression by foreign powers" (59). Thus, to uncover the underlying source of legitimacy, we must look to how Machiavelli details a prince should defend his kingdom and sustain peace with his subjects.
The first method of legitimizing power is through military defense. "If a prince has fortified his town well…then an enemy will be very circumspect in attacking him…it is obviously not easy to assault a town which has been made into a bastion" (36). The logic behind Machiavelli's proposition is based on rational thought. An enemy is less likely to attack a town when it is expected that he will suffer a great deal of casualties. Thus, the fortified town not only acts as a defense, but also as a preventative measure against the chance of an attack. Furthermore, Machiavelli contends that principalities should be measured on their ability to stand alone or seek the protection of others. "[T]hose princes can stand alone who have sufficient manpower or money to assemble an army equal to an encounter with an aggressor" (36). Accordingly, a prince must be able to match or best any threat that may present itself or risk losing his state. However, he cannot raise an army composed of mercenaries or auxiliaries, rather it must be composed of his own subjects. "I conclude, therefore, that unless it commands its own arms no principality is secure; rather it is dependent on fortune, since there is no valour and no loyalty to defend it when adversity comes" (47). What Machiavelli means is that professional soldiers, native to the state, will fight with honor, whereas mercenaries only fight for money and have no loyalty and auxiliaries do not have the proper training and discipline. Ergo, the first stage, military defense, of legitimizing power is accomplished through strong fortifications, the ability to raise an army of greater or equal strength of the enemy, the ability to stand alone in battle, and with an army of his own professional soldiers.
The second step to have legitimate power is through a prince's ability to preserve domestic tranquility. The first step in keeping order in any realm is to have laws; Machiavelli declares that good laws are consequence of the ability to enforce them. "You cannot have good laws without good arms, and where there are good arms, good laws inevitably follow" (40). As previously stated, he believes that the ends justify the means; that sometimes severe chastisements are often required for the benefit of a peaceful state. "So a prince must not worry if he incurs reproach for his cruelty so long as he keeps his subjects united and loyal. By making an example or two hell will prove more compassionate than those who, being too compassionate, allow disorders which lead to murder and rapine" (53). Machiavelli expresses his belief that it is ultimately better for a prince criticized for his treatment of a few than to risk losing the entire public into chaos. Following suit, he answers the infamous question, is it better to be loved or feared? "It is far better to be feared than loved if you cannot be both. One can make this generalization about men: they are ungrateful, fickle, liars, and deceivers, they shun danger and are greedy for profit; while you treat them well, they are yours. They would shed their blood for you, risk their property, their lives, their sons, so long, as I said above, as danger is remote; but when you are in danger they turn away" (54). Through his realist perspective, Machiavelli believes that in order to foster peace,, and as such legitimizing power, a prince must instill fear into his subjects. He rationalizes this conclusion by holding that love does not make men loyal in the face of danger. Rather it is only fear that forges the strongest devotion. "For love is secured by a bond of gratitude which men, wretched creatures that they are, break when it is to their advantage to do so; but fear is strengthened by a dread of punishment which is always effective" (54). While fostering a sense of fear within one's subjects is of critical importance, Machiavelli notes that the excessive and abusive use of fear will have the reverse effect; the subjects will hate the prince and wish to overthrow him. It is for that reason that he states that a prince must "avoid anything which will make him hated and despised" which undoubtedly will come about if he "is rapacious and aggressive with regard to the property and the women of his subjects" (58). Consequently, the second step to legitimate power is via strong arms, severe retributions, and instilling a sense of fear in his people. So long as a prince doesn't abuse cruelty and fear as to be hated, he will have succeeded this stage.
Power is legitimized through a prince's ability to ward off and defend against foreign opposition and safeguard internal lawfulness. These legitimizing factors are accomplished, first with the former through strong fortifications, the ability to raise a formidable army and stand alone in battle, and with an army of his own professional soldiers, and next the latter by having arms to enforce laws, harsh punishments for those threatening peace, and fear to keep his subjects loyal. Machiavelli preaches that the ends justify the means; that a prince must do what he must to preserve order or risk the entire populace descending into mayhem. However, he cannot be too cruel or instill too much fear, for his citizens will hate him and cause a greater threat. If a prince can master these strategies, Machiavelli would insist that his power is legitimate.