The Penumbrae asked the Shadow,
“A moment ago you were looking down
   and now you are looking up;
a moment ago you were sitting down but now,
   you are standing up;
a moment ago you were walking,
   but now you have stopped.

Why is this?”

The Shadow replied, “Honored Sirs,
why do you ask me about such
insignificant subjects? They are all
my movements but I do not know
how they take place. I am like
the shell of a cicada or the shed skin of a snake
–only seemingly real.

In the light of the sun
   I appear;
in the darkness and in the night
   I fade.

Am I dependent on the substance
from which I am projected?
The substance itself is dependent
on something else.

When it comes,
I come with it;
When it goes
I go with it.
When it comes
under the activity of vigorous yang,
I follow it.
As we are both brought forth
by the vigorous yang,

What is there to inquire?

Zhuangzi trans. by Hyun Höchsmann and Yang Guorong, Book 27, Metaphorical Language

The thought experiment is conceived as a brief conversation between two imagined intelligences. Imagine them as you will… Perhaps as a dialog of two smurfs!

A question draws attention to ordinary changes in bodily position. Sometimes you look up, and sometimes down. To be asked “why” as if you had a reason, any reason – isn’t just a silly question. To inquire compels attention to a segment of the flow, that continuous transformation of things. To ask yourself, or to be asked causes one to recognize a segment, a thin slice if you will, of unrelieved change as real. Assuming, by virtue of the focus against a background of “looking down” illuminating the now of “looking up”, surely you caused the change, so tell me “why” you looked up…

The Shadow rightly responds to say the question itself forces attention to an act that matters as little as a discarded shell of a cicada, or the cast-off skin of a snake. Sure, I claim the eye movements as my own, but have no idea “why” the change took place. Everything depends upon the change-dynamic of everything around it does it not? The external stimulus of photons striking the retina are processed by the primary visual cortex, triggering a consequent movement of the eye upward, etc., etc.

Everything depends upon everything else. The Buddhist tradition of thought features a similar assessment of change, and of “the real.” The Buddhist term is co-dependent origination. This is a good word to keep in mind. I have never forgotten it since having learned many years ago.

Unable to answer the queries with a definite cause, the uncertainty is deeper than simple ignorance. Eye movement depends upon a host of supporting conditions, themselves subject to subordinate factors.

What is real, depends entirely upon context. Manifestation, or to dis-appear depend upon the availability of light as an example.

Of course you may ask, – but I wouldn’t know what answer might satisfy.

Its only turtles all the way down…