This particular biography is very valuable to understand the framework for the contribution of Tsongkhapa to Buddhist philosophy as well as some of his unique positions on more obscure philosophical points. It uses his literary contributions during various periods as the basis of discussion for the different phases of his life.
It is important to understand Lama Tzongkhapa in terms of his scholastic contributions because it is through those that we can understand the uniqueness of his philosophy. Devotional hagiographies can be inspiring but LTK's view cannot be understood through devotion or faith alone, because a great amount of his energy was put into developing his philosophical framework.
Tsongkhapa should not be merely a devotional figure that we pray to if we consider ourselves students of the Gelug tradition, but a role model for trying according to our capacity to consider the deeper aspects of the Buddhist teachings, and then integrate them into our lives with meditation.
Tsongkhapa formulated clearly the philosophy for which he is best known some ten years after finishing the Golden Garland. He characterized the vision that led him to his philosophy as a pristine Middle Way *Prāsaṅgika-madhyamaka. Reflecting back on his insight, he would write in his In Praise of Dependent Origination (brTen 'brel bstod pa trans. by Tupten Jinpa,
“Nonetheless, before the stream of this life
Flowing towards death has come to cease
That I have found slight faith in you—
Even this I think is fortunate.
Among teachers, the teacher of dependent origination,
Amongst wisdoms, the knowledge of dependent origination—
You, who're most excellent like the kings in the worlds,
Know this perfectly well, not others.”
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), 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).