Buddha Nature is said to exist in two forms. When it’s covered over by kleshas, the defilements, it’s called tathagatagarbha—Buddha embryo or womb.
When those defilements don’t exist anymore, it’s called Dharmakaya. Dharmakaya is the universal body of the Buddha, the Body which encompasses all of existence. The Dharmakaya is said (in the Nirvana sutra for instance) to have four qualities: self, bliss, eternity and purity.
When we hear that, it doesnt sound like Buddhism. In fact, it sounds like the complete opposite of. everything that we’ve been taught about no self, impermanence and suffering. Indeed those four qualities are the opposite of the four qualities which we’re told characterises samsara: suffering, the belief in a personal, continuing self, impermanence and the kleshas,-—the mental impurities.
In her book ‘Buddha Nature’, Sallie King says that the Dharmakaya isn’t about establishing a new self. Rather, it’s a creative and appropriate response to Nagarjuna. Her argument is that Nagarjuna’s method of subjecting all concepts to destructive analysis leaves us with a conception of emptiness which is negative.
In his time – and now too – Nagarjuna is often criticised (unfairly and incorrectly) as a nihilist, because the positive side of his teaching is ignored, because it’s not explicit in his principal writings. It’s there by inference.
In that way, it’s quite similar to the Buddha, who doesn’t describe the state that the meditator is in when they leave their misconceived conceptual world—when they leave their adherence to a fixed sense of self—it’s simply left for the practitioner to discover, because explication would leave the practitioner still mired in a conceptual position.
Likewise, when Nagarjuna clears away all the erroneous, conceptual structures he doesn’t tell us what the ground, which is left, looks like. The suggestion Sallie King makes is that after Nagarjuna, the emerging Mahayana tradition took a turn towards talking about emptiness in positive terms to remedy this misunderstanding which led to nihilism. Compassion was further emphasised, for the same reason.
The various sutras that we associate with that were turbocharged in impact because of the fortunate coincidence (for them) of their appearance in the early centuries of the common era. This coincided with the reception of Buddhism in China. Because the positive language of those sutras was much more in keeping with the positive view the Chinese had of the world (rather than a quite pervasive view in the Indian spiritual traditions that the world was something that we require to be liberated from), these sutras thrived in their new environment.
Careful analysis of the texts has made it clear that people no one thought that the Dharmakaya or the Tathagatagarba was a ‘something’, contravening emptiness. Rather, it was a positive interpretation of emptiness, so for instance, in the Buddha Nature Treatise, there’s the following passage,”Buddha Nature is the thusness revealed by the dual emptiness of person and things. If one does not speak of Buddha Nature then one does not understand emptiness.” The author is clear that you need to see these concepts through the lens of Emptiness.
And if we also see these concepts through the lens of Practice then it seems to me that Dharmakaya, the universal body of the Buddha, is an experientially accurate way of describing our experience sometimes in Zazen—of non-separation, of the the split between ourselves and the world and the internal splits that we have dropping away, which Isso Fujita calls one piece Zen.