Conceptual knowledge

The I-consciousness, which is the very essence of luminosity, is not a concept (vikalpaḥ), although it is informed by language (vāgvapuḥ). For a concept is an act of ascertainment (viniścayaḥ) presenting a duality (dvayākṣepī).
-- Uptaladeva, 900s AD
Conceptual knowledge happens through a differential process.