The ground of diminution lies in the not-self
Passivity is posited as a QUALITY opposed to reality, as NEGATION ( not simply as a lesser quantum of activity; . . . )
. . . the ground of a quality is called its real ground.
By means of the concept of substantiality, activity in the self (accident in the self) leads to the positing and determining of a passivity ( NEGATION ) therein.
Hegel : The Phenomenology of Spirit. tr. Terry Pinkard (2012)
Hegel : Enzyklopädie der philosophischen Wissenschaften im Grundrisse
Hegel : The Encyclopaedia Logic ( with the Zusatze ). tr. by T. F. Geraets, W. A. Suchting, and H. S. Harris, 1991