Emptiness is not something like just remaining there without having thoughts or anything at all. It is said in the scriptures that if one does not know how to meditate properly on emptiness, then one can fall into the wrong way. To correctly establish the ultimate nature as emptiness, investigate the true nature of mind. Maintain this through the practice of meditation.
Emptiness which is merely empty and the emptiness which is the nature of mind are different. The first emptiness is just nothingness. This kind of emptiness is shown by the example of ‘the horns of a rabbit’. It is just not there. But the emptiness of the mind is different. It does not have any form, colour or shape. It is not existent, and at the same time, it is everything. It is that which creates all of Samsara and Nirvana.
-From Kyabje Penor Rinpoche’s teaching given on 12th November, 1999. (The complete teaching here)
This emptiness is not a mere nothingness. Though there are elaborate scriptures and logical treatises expounding emptiness, it can be recognised in a practical way by just turning inward and investigating one’s own mind. Kyabje Drubwang Pema Norbu Rinpoche (Penor Rinpoche) explained it in a simple way as quoted above.
To recognise the emptiness (śūnyatā) of all phenomena is crucial as the way of perfect awakening. This emptiness means that everything is empty – objects of perception as well as the subjective self perceiving it, matter and mind, all experiences are all empty. Everything arises in dependence upon causes and conditions and everything vanishes with the change of causes and conditions. There is nothing that can stand by itself, truly existing, immutable, without any need for supporting causes and conditions. When we cling on to the ideas of a Self that perceives the world and a world that is perceived, we create dualistic patterns of solidity. Then, we have solid suffering and solid happiness. We have solid tension and solid worries in fighting with solid suffering. In reality, all this happens in an empty mind. When we recognise emptiness of all phenomena, we stop clinging to phenomena. Leaving everything where it is, everything arises and vanishes in its own place leaving no trace of suffering.