The history of Buddhism can, rather than being seen as a history of ideas, more usefully be seen, to a significant extent, as the creative development of metaphors over time.
Unlike ideas, metaphors are intrinsically part of us. They arise naturally in us all the time. We dream and live within them. We respond to them in a different way than to ideas: in a far more intimate way. ‘Ideas’ are bestowed on us by our opponents.
An example of the development of metaphor in Buddhism is sky flowers. Sky flowers originated as a way of talking about delusion. Just as a person with cataracts would see colors and shapes in the sky which appeared to be flowers, when in fact there was just sky, ignorant people see a self when there is only dependent arising.
In sky flowers we can understand delusion. Delusion isn’t an actual obstacle that we need to overcome, it’s more a recognition that we have been seeing incorrectly. The metaphor ties together related tropes in Buddhism: Seeing, Space, Non-Obstruction, Emptiness and Illumination ( the word for ignorance in Sanskrit is avijya, darkness, the absence of light)
This originating metaphor is then taken on by the Yogacara school to illuminate their position that whilst experience is real (so the person with cataracts is actually experiencing sky flowers) the underlying reality which that experience purports to represent isn’t real. We can never know the world in itself, we can only know our experience. There are obvious similarities with another frequent metaphor: the dream.
When we later come to The Sutra Of Perfect Enlightenment, sky flowers is used as one of the practices of meditation to get us over a conundrum—if there’s no self, why do we need to practice? Surely we just need to realize that the true nature of things is Emptiness? That’s the sort of naturalistic fallacy which has plagued Zen from the time of The Platform Sutra, in which Hui-neng, directly perceiving reality through hearing a passage from The Diamond Sutra ( and not meditating at all) is deemed far superior to the seasoned meditator Shen-hsui.
The Sutra Of Perfect Enlightenment, to counter this, uses sky flowers as a way of dramatically showing that, in a sense, we need to provisionally affirm the self to start to practice.
But once we do, our habitual ideas of self are progressively undermined by our actual experience, much as a fictional fraudster would, as it were, undermine himself by progressively revealing his various frauds, culminating in his fraud of self-creation.
Dogen, three centuries or so after The Sutra Of Perfect Enlightenment, takes advantage of the double meaning of sky in sky flowers to talk about the flowers of emptiness.
And then in his hands, rather than a specific metaphor to talk about delusion it becomes a generalised way to talk in a wonderfully original way about the interdependent nature of reality. That very creative use of metaphor is characteristic of Dogen’s genius.
(He does something similar with metaphor of the ocean and the waves which he radicalizes in a brilliant way in his poetry)
Later on from Dogen we have the Korean monk Kihwa who identifies sky flowers with the sense of the individual self, the individual body, and the sky as being the dharma body—the body of all reality.
This is what is meant by turning the wheel of dharma. Rather than learning and replicating ideas or metaphors we take them into ourselves, make them our own flesh then creatively respond with our whole being. To do this is essential, because it ensures the continuation of Buddhism as a dynamic community of practitioners spread over space and time, creating new fabric from the same threads, so the miraculous garment will not fall into nothingness.