The empty circle, which is called Enso in Zen, is a symbol of Reality.
Some also call it "The Circle of Illumination ", others call it "The Infinite Circle "
The Ensō (円 相) symbolizes the infinite, the void, the 'non-thing', the perfect meditative state Satori (the experience of spiritual awakening, in which there is no longer any difference between the observer and the observer).
The traces are drawn with a single stroke. It will be all the more energetic and perfect the more its "author" is no longer such, that is, it does not act in the name of itself but as a pure expression of the reality that directly involves us.
The Enso is at the same time a symbol of reality and of our capacity to understand it, a symbol of the emptiness of the world and of our own emptiness, which powerfully acts as an existential opening towards reality.
Elena Diaco - Emptiness