In this thesis, I consider the views of Pramatha Nath Bose (1855-1934) as an example of Hindu revivalist appropriations of evolutionary ideas and degeneration to advance anticolonial, socially conservative politics in early twentieth century colonial India. I show that Bose drew from metropolitan evolutionary thinkers such as Thomas Henry Huxley, Herbert Spencer, and Alfred Russel Wallace, amongst others, to present a model of social evolution that proclaimed the superiority of Hindu civilization and thus challenged the racial and civilizational hierarchy underpinning colonial rule. I further contextualize his views in relation to contemporary debates about social reform to argue that the evolutionary discourse equipped him to defend Hindu customs, practices, and institutions from reformist criticisms. Similarly, I examine his appropriation of the trope of evolutionary degeneration to present degeneration as a condition inherent to the contemporary West and in India only as a result of colonial rule and the deviation of middle-class Indians from the organically evolved Hindu way of life. Additionally, I argue that Bose’s organicist conception of society and Lamarckian explanation of degeneration enabled him to defend aspects of Hindu society that were increasingly coming under attack from progressive sections of the nationalist movement such as the practice of early marriage and the caste system. Therefore, I show that evolutionary and degeneracy theories were put to work to perform a dual function in the Hindu revivalist movement by presenting both the inferiority of Western civilization and the futility and dangers of Western-oriented social reforms — thus, combining ideas of natural evolutionary processes with anticolonialism and social conservatism.