Lü Dongbin's The Secret of the Golden Flower chapter, "The Light of Nature and the Light of Cognition," distinguishes between "natural light" (inherent, pure awareness) and "cognitive light" (consciousness arising from thought). The text emphasizes the importance of cultivating natural light through the practice of "returning the light," a method of achieving enlightenment by releasing attachment to thoughts and external stimuli. This process involves recognizing that clinging to perceptions leads to the cycle of rebirth, whereas letting go of these attachments reveals the true, unconditioned self. The text uses Buddhist concepts and analogies to illustrate the subtle yet crucial difference between these two types of light and the path to achieving true emptiness.