How Deception Arises
... when (appearances) manifest from the ground, the creative dynamic of energy manifests naturally as cognition, which is the clarity and intrinsic awareness capable of analyzing objects. Through non-recognition of the nature (of appearances), three aspects of unawareness manifest in conjunction with appearances. The unawareness identical in nature (with intrinsic awareness), the cause (for deception), is a failure to recognize that cognition is itself (intrinsic awareness). Co-emergent unawareness is the simultaneous arising of cognition and a failure to recognize its actual nature. Conceptual unawareness is the apprehension of self-manifestations as something "other."
-- Jamgon Kongtrul Lodrö Thaye the Great, Myriad Worlds. Translated & edited by the International Translation Committee founded by the V.V. Kalu Rinpoche, Snow Lion Publications, Ithaca, 1995, page 212.