By mindfully and discerningly attending to all kinds of perceptual appearances—material, mental, and otherwise—we can begin to distinguish between what appears to be our immediate sensory experience and our conceptual projections. In doing so, we start to discover the extent to which our waking experience is illusory. But the dreamlike nature of our experienced world may go a lot deeper than that. In the Perfection of Wisdom Sutras the Buddha makes the more radical claim that the world of our waking experience is fundamentally no more real than a dream. In a non-lucid dream, we mistakenly grasp onto all objective and subjective appearances as if they were inherently real, bearing their own intrinsic existence. Likewise, in the normal (non-lucid) waking state we do the same thing, imagining the physical world to be really “out there,” existing independently of our conceptual constructs, and we grasp onto our thoughts and other subjective experiences as being really “in here,” existing by their own inherent nature. In philosophical terms, we reify—or project as a substantial, independent existence—everything we experience while awake and asleep.
…Phenomena appear to exist inherently, independently of our conceptual frameworks, and we deludedly grasp onto them as existing just as they appear. But this simply perpetuates the dreamlike nature of experience of all kinds. When you become lucid in a dream, you begin to recognize that things are not as they appear, and now your challenge is to recognize the extent to which things in the waking state are no more real than a dream.