Mahayana Buddhism has two principal pillars: emptiness and compassion.
Emptiness is primarily a skillful means to cultivate non-attachment rather than an assertion about the fundamental nature of things. There’s no ‘Emptiness’ lying underneath Form. Emptiness is itself empty
Compassion (feeling-with) is intimately connected with non-separation.
When we say emptiness and compassion, we can equally say non-attachment and non-separation. With regard to the first, it’s no accident that the most common metaphor for our human condition used by Buddhists is the dream. In the dream we cannot say that there is nothing. Our experience is vivid and immediate, yet there is no essence to grasp hold of. Living in this way is not attachment, but neither is it detachment, which would be grasping ourselves.
Cultivating this attitude in our own life and in witnessing the lives of others, we can understand that we are all living within a dream. And so we can cultivate non-attachment for ourselves and compassion for all beings.
When we turn to zazen, it’s true that to steady ourselves, to solidify our practice, we cultivate non-attachment to our thoughts and emotions. But the fundamental practice of zazen is not non-attachment: it’s non-separation. And we achieve this by attempting to practise at a level deeper than that of ordinary perception.
We’re not simply sitting quietly in our familiar world – we are sitting within a new world which is vivid, immediate and momentary. And within which there is no separation between this person and all beings.