Exercise 13-16: Perceptions
(13-14): Impermanence & Craving
Exercise 13-16 are the exercises for attaining full enlightenment and require very deep observation. What we must understand before these exercises is that this world is our mind itself because this world is the object of our mind, or the projection of our mind. In other words, the projection of our mind is this world. The object of mind is the object of perception, the object of perception is the perception (series of notions in the head), so the perception is this world. In other words, the perceived is the perceiver. David Bohm, Quantum physicist, said, "The way we see depends on the way we think." And his statement is consistent with the Buddha's above findings.
In Exercise 13, you deeply observe the impermanent nature (nature of 'emptiness' in terms of time) of all dharmas (object of mind). Because everything is changing, you can observe the impermanent nature of all objects of your mind. And you observe the impermanent nature of all perceptions because all objects of your mind are the projection of your mind (perceptions). Therefore, this world which is the object of your mind is your perception itself, and it has the impermanent nature. In Exercise 14, you deeply observe the disappearance of craving (negative desire). And you deeply observe the disappearance of idea (thought). Therefore, your craving is just an idea and will disappear after a certain time.
(15-16): No-self & Nirvana
In Exercise 15, you deeply observe the no-birth, no-death nature of all phenomena. No-birth and no-death means that nothing can be born and nothing can die. Everything (all human beings, animals, plants, minerals) just continues (keeps living) by changing its forms. So, they can not be born because they have never died, and they can not die because they have never been born. And you deeply observe that everything is made of everything else. In other words, everything else is in everything. Therefore, everything is everything else. You are observing the nature of no-self (nature of 'emptiness' in terms of space) which means that everything is empty of separate existence (separate self). This is the ultimate truth.
In Exercise 16, you deeply observe letting go of all notions (everything). The extinction of all notions is Nirvana. Because you are convinced that all notions are made up by human ego (separate self, fake self) and all notions are wrong, it is easy for you to throw away all notions. If all notions are extinct, there is no object to think about. So, you will be non-thinking completely and be able to attain insight 24 hours a day as awareness (non-separate self, true self). Attaining insight means that without making any efforts (without thinking), your calm mind reflects the outside reality like still water (mirror), and your clear mind sees through the inside reality. This is the full enlightenment, so you are fully awake.