Faculty of Hetu Evam Adhyatma Vidya (Logic and Spirituality) is one of the foremost faculties of the Institute established at the time of the Institute’s inception. Initially it started with two departments, Mool Shastra and Sampradaya Shastra, a third department, Bon Sampradaya Shastra was added in 1990. Mool Shastra refers to ancient Indian Buddhist treatises, which are studied here at the Institute through their Tibetan translations, as almost all the original Sanskrit are lost. Sampradaya Shastra refers to commentarial texts written by Tibetan Buddhist masters from the four Tibetan Buddhist Sampadayas: Nyingma, Kagyu, Sakya, Gelug on the treatises (Shastras) of the Indian Buddhist masters. Hence, Mool Shastra and Sampradaya Shastra course curriculums consist of Indo-Tibetan Buddhist Philosophical studies rooted in the philosophical, epistemological, ontological, phenomenological, metaphysical, hermeneutical works of the Indian Buddhist masters of Nalanda Buddhist Tradition such as Acharyas Nagarjuna, Dignaga, Chandrakirti, Dharmakirti, Shantideva, Vasubandhu and many others. Bon Sampradaya Shastra refers to works of the Bon masters on Bon religious tradition, an indigenous Tibetan religion with its own corpus of literature.