Vaisesika Sūtra 2.2.22

तुल्यजातीयेष्वर्थान्तरभूतेषु विशेषस्योभयथा दृष्टत्वात् ॥२२॥

tulyajātīyeṣvarthāntarabhūteṣu viśeṣasyobhayathā dr̥ṣṭatvāt ॥22॥

[तुल्य (tulya): Equal; जातीय (jātīya): Of the same kind or species; एषु (eṣu): Among; अर्थ (artha): Meaning or object; अन्तरभूत (antarabhūta): Having different natures; एषु (eṣu): Among; विशेष (viśeṣa): Special or specific; अस्य (asya): Of this; उभययथा (ubhayayathā): Both ways; दृष्टत्वात् (dṛṣṭatvāt): Due to being observed;]

Among the same kind that are equal, and among those with difference, the particularity among both are observed.