This dissertation presents a study of the doctrines and exegetical system presented in The Commentary Called "Brightening of the Lamp" (Pradipoddyotana-nama-t&dotbelow; ika), a text composed by the Buddhist intellectual Candrakirti of the so-called Noble System associated with Nalanda monastery in the second half of the first millennium C.E. It aims to situate this exemplary document of Vajrayana scholasticism within the context of pre-modern Indian intellectual practices such as classical Sanskrit commentary and Indian Buddhist hermeneutics. Broadly, the study examines the role of Esoteric Buddhist scholastic commentary in the assimilation into an Indian Buddhist mainstream of practices and symbolic systems apparently at odds with Buddhist values and normative monastic codes of conduct. Composed mainly in Sanskrit and preserved mostly in Tibetan translations of the turn of the second millennium C.E., this literature articulates a synthetic, "Vajra Vehicle" (Vajrayana) discourse within the cosmological and institutional frameworks of Mah™ay ana Buddhism. The dissertation singles out the Pradi poddyotana as an exemplary document of this synthetic discourse and argues that it was instrumental a momentous reworking of Mah ayana orthodoxy and orthopraxis, which in turn made possible the refashioning of monastic centers such the great Northeastern Indian monastic vihara of N alanda into centers of Tantric Buddhist practice and instruction.