Publisher Summary This chapter focuses on the legitimacy of mathematical models in Indian cosmology. The importance in classical Indian culture of deities, religious devotion, and the general spiritual theme of transcending the human and mundane is a very familiar concept to Westerners. In the eighteenth and nineteenth centuries, it became a contentious question for many Indians and Anglo-Indians whether and how mathematics and the divine had coexisted in the “indigenous” Indian (Sanskrit) tradition. Though some colonial commentators on Sanskrit astronomy were frankly contemptuous of the entire tradition, others—especially Orientalists with some personal experience of and enthusiasm for Sanskrit literature—inclined to a more nuanced view, which asserted that “Hindu” sciences in earlier times accepted mathematically rigorous models of the cosmos similar to those of the classical Greeks Under the influence of Graeco-Babylonian and Hellenistic sources, more comprehensive astronomical treatises usually called siddh¯antas—which in this context may be rendered by “astronomical systems”—began to appear. At the latest a siddh¯antic model was established that assumed a spherical earth only about 5000 yojanas in circumference, suspended in the middle of a sphere of fixed stars.