"El Filibusterismo" delves into the theme of revolution as a means to achieve social and political reform. Simoun's character embodies the idea that drastic measures are sometimes necessary to overthrow an unjust system. This theme resonates deeply with the historical context of the Philippines' struggle for independence from Spanish rule.

The novel highlights the various forms of social injustice prevalent in the Philippines during the Spanish colonial period. From the exploitation of the poor to the corruption within the church and government, Rizal exposes the systemic issues that plague society. This theme serves as a critique of the colonial powers and a call to action for the oppressed.

The transformation of Ibarra into Simoun symbolizes the complex nature of identity and the impact of personal experiences on one's beliefs and actions. This theme explores how individuals evolve in response to their circumstances and the lengths they will go to achieve their goals. It also reflects the broader national identity crisis faced by the Filipino people under colonial rule.