nāsato vidyate bhāvo nābhāvo vidyate sataḥ |
ubhayorapi dṛṣṭo'ntastvanayostattvadarśibhiḥ ||2.16||
For the unreal (mithyā), there is never any being. For the real, there is never any non-being. The ultimate truth of both (the real and the unreal) is seen by the knowers of the truth.
Analysis of existence and non-existence is done in this verse.
Asat - non-existent doesn't mean it isn't there at all, but it just doesn't exist independently on its own. And sat - existent exists independently of anything else. For example cold and heat are asat, not just because they depend on other factors like season, time, etc to be there, but they also need a revealer / perception to determine their existence. At twenty degree celsius, coldness is feel by certain people, but others don't feel the existence of the coldness at all.
What doesn't need revealer to determine its existence? To proof the existence of any given object, there must be a revealer to reveal its being. Any object can be revealed by our senses, senses are revealed by mind, and mind is revealed by me - consciousness. Who reveal the consciousness? Consciousness is self revealed, and as basis for others to be revealed. I - cit - consciousness is the only sat - existence which exists independently and as the basis for others to be exist. Therefore any object in the world is asat because it depends on the subject/objectifier. When there is no objectifier, nothing is objectified.
Here we are interested to the revealer-revealed relationship (subject-object relationship) while analysing sat and asat, because the entire world consists of I - the subject and everything excluding me - the object. All my problems lie on the relationship between I - the subject and object which I perceived (everything other than me including my body-mind-complex). No object is the cause of problem by its own. It only becomes the source of problem (or happiness) when there is relationship between the object and its perceiver.
Asat is not total non-existent, just like a pot, we can't dismiss the name, form and function of the pot itself. But it doesn't always exist. When the pot is broken, the name, form and function are also gone, but the pure existence as the basis for the conditioned / qualified existence (conditioned by pot's name and form) never ceases away. In the same way, when all my perception towards the entire world is suspended, the world lost its being. In the same time when the entire world is not there to be objectified, the objectifier also is dismissed. When subject and object are dismissed, what left is only existence which lend its being to the objectifier and objectified. This existence is the ultimate truth of the entire world, which is indestructible (2.17).