Between Reification and Nihilism: The Fourfold Investigation as Yogācāra Contemplative Method

This paper argues that the fourfold investigation (catasraḥ paryeṣaṇāḥ) and the fourfold thorough knowledge of things as they are (catvāri yathābhūtaparijñānāni), as presented in the Tattvārthapaṭala of the Yogācārabhūmi-śāstra, constitute a central contemplative methodology within the Yogācāra soteriological framework. Drawing on Sanskrit and Chinese sources through philological and hermeneutical approaches, the paper first identifies wisdom (prajñā) as the governing mental factor and establishes the fourfold investigation as a form of vipaśyanā, with the investigation of names as its foundation. It then analyzes the epistemic progression from investigation to thorough knowledge, showing that both things and the thing-only (vastumātra) are ineffable. Finally, the paper demonstrates that these methods correspond to the elimination of attachment of superimposition (samāropa) and diminution ( apavāda), providing the concrete contemplative mechanism for realizing the Yogācāra middle path between reification and nihilism.