The 'consciousness of holding the function and returning to the essence. ' The third of the 'five layers of penetration to the principle of consciousness-only.' In this case the ideogram 末 refers to the subjective view （见分） and 本 refers to the witnessing aspect （自证分）. Since this function is the function of the essence-aspect of consciousness， it is seen as essence （体）. Also， since in the transformations of this essential part of consciousness these are the two aspects of subjective and objective view， these two are seen as function （用）. Since these two views are not separate from the consciousness in itself， in the original essence of the mental function of the subject cognizing the object， these two functions are included. This is also called The 'relativity of substance and function' 体用相对.