Chan presents emptiness (śūnyatā, kong 空) as the fundamental nature of all phenomena, including what is conventionally called “self” and “mind.” All dharmas are understood to lack any fixed, independent essence; they arise only through causes and conditions and therefore have no permanent, unchanging core. Emptiness here is not a doctrine of sheer nothingness, but a way of seeing that whatever appears is contingent, interdependent, and without a separate self-nature. This insight applies equally to thoughts, emotions, and perceptions, which are observed to arise and pass away without any solid owner behind them. Thus, emptiness is the recognition that the sense of a permanent self is itself a construction without inherent existence.

Rather than treating this as a purely philosophical thesis, Chan insists on direct, experiential realization. Practices such as sitting meditation (zuochan), the cultivation of no-mind (wuxin 無心), and the use of koans and paradoxical dialogues all aim at cutting through conceptual elaboration so that emptiness is seen immediately. In such practice, thoughts are neither grasped nor rejected; their insubstantial, fleeting character becomes evident, and the grasping, discriminating mind begins to dissolve. This is often described as sudden awakening, a shift that occurs when conceptual thinking falls away and the empty nature of experience reveals itself without mediation.

At the same time, Chan emphasizes that emptiness is not something separate from the world of form. Drawing on the Mahāyāna teaching that “form is emptiness, emptiness is form,” it presents emptiness and appearances as non-dual: everyday activities such as eating a meal or hearing a bell are not distractions from emptiness but its very expression when seen clearly. Because all things are empty of fixed essence, they can manifest freely in their suchness, without needing to point to anything beyond themselves. This insight, when integrated into daily life, loosens attachment and softens the boundary between self and others, allowing compassionate and responsive activity to arise naturally.

Chan also warns against turning emptiness itself into a new object of attachment. Emptiness is said to be empty as well; it is not a special state to cling to or a metaphysical ground to grasp. When this is understood, practice does not fall into nihilism or into reifying some absolute void. Instead, there is a flexible, unobstructed engagement with whatever arises, informed by the recognition that nothing possesses a fixed, independent nature, yet everything that appears is fully present and complete in that very emptiness.