Catherine the Great's policies had a significant, albeit contradictory, impact on the status and treatment of serfs in Russia. Initially, she showed some inclination towards improving the conditions of serfs, inspired by Enlightenment ideals. However, as her reign progressed, Catherine increasingly sided with the nobility, who were her main support base. Her policies, particularly after the Pugachev Rebellion, which was a massive peasant uprising, strengthened the institution of serfdom. She granted more powers to the nobility over their serfs, which led to harsher conditions and less freedom for the serf population. This approach reinforced the feudal system and contradicted the Enlightenment's humanitarian principles.

Frederick the Great's military campaigns, particularly his aggressive territorial expansions, starkly contradicted his image as an enlightened monarch. While he promoted Enlightenment ideals such as rational governance and cultural patronage, his military strategies were often ruthless and expansionist. The most notable example is the Seven Years' War, where Frederick aggressively pursued territorial gains, leading to extensive conflict across Europe. This militaristic approach, focused on power and expansion, clashed with the Enlightenment values of peaceful progress and rational diplomacy. Thus, his military actions often overshadowed his enlightened reforms, revealing the complexities and contradictions inherent in the rule of enlightened despots.

Philosophical ideas of the Enlightenment played a crucial role in shaping the policies of both Frederick the Great and Catherine the Great. Frederick’s reforms were heavily influenced by his admiration for Voltaire and other Enlightenment philosophers. His emphasis on rationality and efficiency in governance, religious tolerance, and legal reforms reflected this intellectual influence. Similarly, Catherine the Great was inspired by Enlightenment thinkers such as Diderot and Voltaire. Her attempt to reform the legal system with the Nakaz and her efforts to modernize education and culture were deeply rooted in Enlightenment philosophy. Both monarchs sought to apply these philosophical ideas to varying degrees in their governance, aiming to combine enlightened ideals with absolute rule.

Catherine the Great's Nakaz, or Instruction, was a visionary document that sought to reorganise the Russian legal system. It was heavily influenced by Enlightenment thinkers like Montesquieu and Beccaria and reflected progressive ideas of the time. Key features included the call for legal equality, the condemnation of torture and capital punishment, and the advocacy for fair trials and the abolition of serfdom. The Nakaz also emphasized enlightened principles such as the sovereignty of law and the importance of education. Although the Nakaz was never fully implemented, it represented a significant step towards modernising Russia’s legal system and reflected Catherine’s ambition to reform her empire based on Enlightenment ideals.

Frederick the Great's deep interest in the arts had a transformative impact on Prussian culture. He was not only a patron of the arts but also an accomplished musician and a composer himself. Under his reign, Berlin emerged as a significant cultural centre in Europe. He established the Berlin Opera and the Royal Library, inviting renowned artists and philosophers, including Voltaire, to his court. This cultural flourishing led to a vibrant artistic environment, which was instrumental in the development of the Prussian identity. His support for the arts also reflected the Enlightenment principle of nurturing intellectual and artistic pursuits, further embedding these ideals into Prussian society.