A philosopher and scholar, Sarvepalli Radhakrishnan was also a statesman, even to the extent of serving as India's president from 1962 to 1967. Brought up as a devout Hindu but also educated in Christian missionary schools, Radhakrishnan's philosophy often was comparative, finding lines of convergence and divergence between East and West. Based in Vedantic idealism, Radhakrishnan affirmed the necessity of an experience of the absolute as the basis of any truly profound grasp of reality. In this regard, he focused his scholarship on the great classical texts of the Indian tradition: the Upanishads, the Bhagavad Gita, the Brahma Sutra, and the various Vedantic commentaries. However, Radhakrishnan's fundamentally mystical, idealistic dimension did not lead him to renounce the material world. On the contrary, he affirmed action in the world as the expression of the transformative power of the absolute itself. Unlike many traditional Vedantists, Radhakrishnan did not view the material world with all its differentiation as unreal; rather, it is simply not absolute in itself. Spiritual and moral value ultimately derives from something deeper. In this way, he established a metaphysical ground for religious tolerance, an openness he brought to his own activities in the political sphere.