Tsongkhapa, the founder of the Gelug tradition, was a revolutionary reformer who based his reinterpretations on his exhaustive study of the Indian and Tibetan Buddhist texts, his impeccable logic, and his intense meditation. He reinterpreted many teachings, particularly concerning the assertions of the Svatantrika and Prasangika tenet systems. He radically reformed the understanding and explanation of cognition theory – how we know things conceptually and non-conceptually. Related to cognition theory, Tsongkhapa’s presentation of voidness was also new. The earlier schools – Kagyu, Nyingma, and Sakya – assert that the voidness validly cognized conceptually and non-conceptually are different voidnesses, while Tsongkhapa said they’re the same. He stated that to go from the conceptual cognition to the non-conceptual cognition of voidness requires understanding the voidness of voidness.