" In the natural field, I am going to find ambiguous beings, which are neither waves nor particles. What is the wind perceived? Someone? A thing? A phenomenon? It is all three at once: a continuation of movement without mobiles, of behavior without subjects, as the tail of the comet or the shining star--that is, probable beings are led back to a sheath of probabilities--after all, what is reflected is not a unique individual, it has multiple functions--and to nondeterminate beings without this indetermination rendering them ordinary (such as the board behind me, a marginal object), to negative beings whose entire essence is to be absence, and to beings neither finite nor infinite. The gestaltists tried to mark the limit of the visual field, but it is impossible to define this limit by a black border: to see black is not to see nothing. All the objects at the limit recover this indetermination. "
― Maurice Merleau-Ponty , Nature: Course Notes from the Collège de France