 Tsongkhapa first sets forth this mature philosophy linking dependent origination and emptiness in a special section at the end of his Great Exposition. There, in the context of an investigation into the end-product of an authentic, intellectual investigation into the truly real (Sk. tattva, Tib. de kho na), and into the way things finally are at their deepest level (Sk. tathatā, Tib. de bzhin  nyid),[2]  he says you have to identify the object of negation (Tib. dgag bya), i.e., the last false projection to appear as reality, by avoiding two errors: going too far (Tib. khyab che ba) and not going far enough (Tib. khyab chung ba) (Drefus et al, 2011, chapter 5).