The first main theme is politics. The Prince was written as a manual for new rulers who desired complete control. Machiavelli argued that the prince must maintain sovereignty over his subjects. Virtuous qualities are not required for effective leadership, as being feared is more important than being known for admirable traits. To maintain political power, the prince must utilize force when necessary and keep his motives hidden from the public. 

The second main theme is fate and chance. The prince can't assume that everything will go his way. So he must be prepared for what is beyond his control. Machiavelli encouraged caution and preparation, rather than simply falling victim to fate. It's imperative that the prince must use his free will in order to change his methods and adjust to various situations. 

The third main theme is deception. While public perception is key to gaining loyalty from commoners, Machiavelli argued that lying is necessary to maintaining control. The prince needs to view his subjects as weak and volatile so that he can take advantage of their fickle desires. Relying on moral relativism, the prince is able to break his promises to the people and create reasoning that appears justifiable in that moment.

One theme in The Prince is human nature. Machiavelli has a rather bleak view of humanity in that he believes that it is dangerous for a prince to win the love of his subjects. It is also dangerous for a prince’s subjects to be perpetually afraid of him. Machiavelli believes that the prince needs to be perceived as just, whether he really is or not.  He should be respected—that is the fine line between being loved and hated.  

Another theme is military prowess.  The prince should be an expert on the military and through this he will be able to ensure successful negotiations with other nations.  Machiavelli believes that the prince's soldiers need to be homegrown so that they will fight for their own land instead of out of love for one's leader or love for money.  At the end of the book, Machiavelli also argues for Italian nationalism and a united army.  This is a unique thought  because at that time Italy was a collection of feuding city-states. 

Another theme is history.  Machiavelli identifies other leaders throughout history, from contemporaries in the Italian city-states, to Roman leaders from antiquity.  By using concrete examples, Machiavelli is not writing an abstract treatise; rather, the book is more like a practical "how-to" for the ideal prince to govern.

Theme 1: proper politics, effective governing, and the correct way to use the military and fight a war.  Machiavelli's big change from the norm at the time was to see the military as a natural extension of the political part of government.  He purported using the military to help get political agendas accomplished.  Not so much within the country's own borders, but to help with international relations.  He figured that as long as the neighboring principalities posed a threat, why not look at them through a military point of view. 

Theme 2: I will call it a free will theme.  Machiavelli called it prowess vs. fortune.  Modern day scientists would call it nature vs. nurture.  Machiavelli spends a fair amount of time analyzing how and why a prince might be successful.  Is it because of their own ability (prowess), or is it predetermined by their bloodline and circumstance (fortune)?  In other words, is their success because of their experiences and personal decisions (nurture), or is solely because of their DNA (nature).  Machiavelli doesn't side with either case completely.  He believes that both pieces are integrally related.  He believes that a person (prince) can have great free will control over their circumstances, but also believes that total control is just not possible.