Thinking becomes false because of the interference of sanskaras* accumulated during the process of the evolution of consciousness. The function of consciousness is perverted by the operation of sanskaras, which manifest themselves as desires. Through many lives, consciousness is continually being burdened by the aftereffects of experience. The perception of the soul is limited by these aftereffects. The thinking of the soul cannot break through the hedge created by sanskaras, and consciousness becomes a helpless captive of illusions projected by its own false thinking. This falsification of thought is present not only in cases where consciousness is partly developed but also in man, where it is fully developed.
-Discourses 7th Ed, p17
*Sanskaras: impressions; accumulated imprints of past experiences, which determine one’s desires and actions.