Beginning in the late eighteenth century, the Age of Enlightenment set in motion revolutionary ideals that would ultimately destroy the traditional feudal system and begin the rise of nationalism in Europe. This "rise of nationalism" will last more than three hundred years, from the birth of the French Revolution to the outbreak of the Second World War. During this period, hostilities and violence between European nations would increase, due to the willingness of their respected peoples to support their given nation's aspirations of territorial conquest and economic dominance, which were seen as guarantees of economic prosperity and invocation of national pride. Subsequently, the fierce defense of their homeland by the European peoples would have proactive and destructive repercussions throughout history. The French economy in the 18th century was on the verge of collapse, due to two costly interventions in the colonial wars across the Atlantic. The Third Estate, which made up the majority of France's population, received horrendous tax rates to bail out the ailing French government, which desperately needed funds to repay the nation's debt. As a result, Rousseau's vision of government in which "a people could only be free if they governed themselves" became incredibly popular among the French population, thanks to the attractive idea that French citizens controlled the government rather than an absolute monarch. However, even though Rousseau did not directly prefer a republic (because he saw representatives as removing power among the unrepresentative population), his ideas regarding the right of people to create their own laws and to actually control the government, indirectly stimulated the creation of the French republic...... half of the paper ......the ise of nationalism in Europe could be identified as both a blessing and a curse, due to its constructive and destructive characteristics. In terms of proactivity, the nationalistic uprisings against monarchical rule in the 18th and 19th centuries (French Revolution) enabled the acquisition of civil rights and liberties among the peoples of Europe. On the other hand, catastrophes such as World Wars I and II were caused by deeply nationalistic nations seeking to preserve their culture through conquest of their enemies. Ultimately, the drive to preserve their respected cultures allowed the European people to achieve extraordinary achievements that led to the modernization of Europe, as well as to carry out unimaginable catastrophes, the carnage of which witnessed by those who survived led them to put question the same principles of nationalism that once united them..