In his mostly Svātantrika interpretation of Madhyamaka philosophy, Jñānagarbha incorporated aspects of Yogācāra philosophy and Dharmakirti's epistemology and therefore can be seen as a harmonizer of the various Buddhist philosophical systems like his student Śāntarakṣita.
He is mostly known for his work "Distinguishing the Two Truths" (Skt. Satyadvayavibhaṅga, Wyl. Bden gnyis rnam ‘byed). This work mostly sought to critique the views of Dharmapāla of Nalanda and his followers. A meditation text named "The Path for the Practice of Yoga" (Yoga-bhavana-marga or -patha) is also attributed to him by Tibetan sources. He also may have written a commentary to the Saṃdhinirmocana Sūtra, a major sūtra of the Yogācāra school. However, it is possible that the author of this text was actually a different writer also named Jñānagarbha.
Jñānagarbha's Satyadvayavibhaṅga analyzes the Madhyamaka "two truths" doctrine of conventional truth and ultimate truth. He defends the role of conceptual thinking and reasoning against those who would eliminate all conceptual thinking and theorizing (i.e., Candrakīrti). However, like other Madhyamikas, the goal of his project is a form of awareness which is free from all concepts, though one which, according to Jñānagarbha, is reachable through conceptual thought. Jñānagarbha held that even though language and reasoning is based on a cause and effect ontology which is ultimately empty and unreal, it can still lead toward the ultimate truth, through a logical analysis which realizes the untenable assumptions of reason and causality itself. (Source Accessed Jan 17, 2020)