Machiavelli makes two main statements about fortune. First, the author claims that the good leader transcends fortune's vicissitudes. Free will, notes Machiavelli, trumps luck. Second, Machiavelli urges rulers to control and command fortune. Fortune is female in the Prince for two reasons. One, females are associated with nature, and Machiavelli uses a metaphor from the natural world to describe fortune as a raging river: "which when in flood overflows the plains, sweeping away trees and buildings, bearing away the soil from place to place; everything flies before it, all yield to its violence, without being able in any way to withstand it," (Chapter 25). Two, fortune is female because men can control it using brute force. Females and fortune are depicted as wild, natural, and untamed. Rulers are by default male and therefore capable of harnessing the power of fortune.

Machiavelli's ascription of the female gender to fortune reflects the belief that women are inherently wild, dangerous, and untamed. Women are, moreover, physically weaker than their male counterparts and therefore unable to stand up to a physical assault. Machiavelli plainly states that "it is necessary to beat and ill-use her," for the good of the state (Chapter 25). The author also claims that women, and fortune, "allow" themselves "to be mastered" by an "adventurous" ruler (Chapter 25).

Just as it would have been deemed just to control a wife by use of force, Machiavelli would note that the virtuous leader must control his fortune. Fortune is female because females are powerful yet easy to control by force. The sexism inherent in the Machiavelli passage only reflects the patriarchy that characterizes almost all human societies. Similarly, Machiavelli's Prince is automatically male because the author assumes only a male would make a good ruler. Still, Machiavelli...

Toward the end of Chapter 25, the author notes that young men are much "less cautious" and less able to control their emotions. Not all men would make good rulers, notes Machiavelli. Those able to control their reactions, and others' reactions to them, are the ones best suited for the title of Prince.
The reasoning behind controlling fortune is sound, even if the metaphor may be spurious. Machiavelli notes that any leader who is easily swayed by fortune is one who loses his power. He gets thrown off-balance by the fluctuations of fortune: too elated when times are good and dejected or angry when times are bad. Wasting energy on fortune dooms a leader to failure.

The effective leader is one who remains calm and controlled under all circumstances and situations. He is like a martial artist. Tides of fortune may rise or fall, and the leader must remain true to his principles to succeed. "A prince may be seen happy to-day and ruined to-morrow without having shown any change of disposition or character," (Chapter 25). Machiavelli also advises against banking on fortune, for a ruler might experience good luck. A ruler relying on fortune would be no different than a worker relying on gambling as a form of income.

Fortune is viewed as being external to the prince, just as a woman is external to a man. The prince's reaction to fortune must reflect his commitment to the state. Keeping the best needs of the state in mind, the prince harnesses the power inherent in both good times and bad. The virtuous ruler is one that avoids hatred by not squandering good fortune.

References

Machiavelli, Nicolo. The Prince. 1515. Translated by W.K. Marriott. 1908. Retrieved Jan 31, 2009 at http://www.constitution.org/mac/prince00.htm