Swami Vivekananda developed a theory of nationalism based on religion. According to him like music each nation had a main note a central theme compared to which everything else was secondary. India's theme according to him was religion and it had to be made the backbone of national life. The future greatness of any nation could be built only on the foundations of its past greatness.
Religion had been a creative force of integration and stability and it helped to retrieve and strengthen even political authority when it became weak. He thus advocated the organization of national life on the basis of a religious ideal.
But religion in his idea was not a set of barbaric customs or a set of dogmas and rituals etc. It was rather the realization of certain eternal principles.
In his view politics and power in India were linked to western influence. Anyone who knows India in his opinion must understand that politics, power and even intellect form a secondary consideration. A religion is one dominant consideration in India. Preoccupation with political power was part of a distinctly western vanity and material tyranny.
He emphasized on individual morality and social change. He believed that a nation is great or good because of the innate greatness, goodness of its people and not because the state so desires and enacts legislations to that effect. Religion is more important since it moulds the individualities and conduct of people makes them great or good. In his view the spiritual tradition of Hinduism calls for resistance to the legalized oppression embodied in the crushing tyranny of castes, kings and foreigners.
Swami Vivekananda's ideas influenced the theory and practice of politics in India.