心識在了知對象的同時，還對自身有反省作用。作為心識認知要素之一的自證分，其重要功能在於它的自證性，即心識對自己的活動本身的一種非對象性的「反觀覺察」。心識的這一「自己認識，證知自己」的功能，不僅在於它是一種觀照實相的高階智慧，更在於唯識觀行的修行實踐中它是轉迷悟、染淨之機樞。本文還涉及與自證分密切相關的一些重要概念如毗婆舍那、依他起、現量等也作了詳細的比較和辨析，並結合修行實踐考察了這一「覺知」功能在「五重唯識觀」中的具體操作和實證。開顯自證分的能動性，以期對恢復唯識學「解行相應」的修行傳統有一定的現實意義和價值。

In every act of perception, consciousness exercises introspection upon itself. So in knowing an object (image), it also knows itself. The introspection, or self-witnessing, is a fundamental function of Svasamvittibhaga (self-consciousness), which is one of the key elements in the structure of cognitions. The introspection is executed on the act itself, not on an object; it’s a reflection upon the consciousness behind the perception. In Vijñānavāda (Yogācāra) Buddhism, the importance of this function of self-cognition (knowing that one knows) resides not only in the fact that it is endowed with wisdom when observing reality as it is, but also in the role it assumes as the hinge point from vijñapti (consciousness) to prajñā (wisdom) in practices. This paper also refers to some key concepts related to Svasamvittibhaga (self-consciousness) such as vipaśyanā (contemplation), paratantra (dependent or relative nature) and pratyaksa (direct perception) for more detailed comparison and analysis. It integrates also practices to observe how this function of cognition is put into practice in “five vijñānavāda-perceptions,” in an attempt to highlight the initiative of Svasamvittibhaga (self-consciousness), hoping to revive two traditional and complementary aspects of learning Vijñānavāda (Yogācāra) Buddhism: understanding and practice.