On the Emptiness of Consciousness
According to the emptiness teachings, human consciousness is empty because of being divisible into parts.
The consciousness involved in looking at a blue vase does not have spatial parts because it is not physical, but it does have temporal parts. It exists as a continuum of moments. Consciousness looking at a blue vase has earlier and later moments in its continuum, and these are parts of a stream of consciousness— no matter how short.
Consider even the briefest moments in a continuum. If even the briefest of moments did not have a beginning, middle, and end, then those moments would have to be indivisible atoms of consciousness, and there would be many non-empty consciousnesses in each moment for the same person. Such indivisible moments could never be shorter than they are, and they could never join with other moments to become a continuum. Nothing would link them together, in which case we wouldn’t have even an illusory sense of the continuity of consciousness.
As Nagarjuna says:
Just as a moment has an end,
so it must have a beginning and a middle.
Also the beginning, middle, and end
Are to be analyzed like a moment.
–From the Dalai Lama’s How to See Yourself As You Really Are