Mmmm...I'm also thinking in terms of cognition. Eg, during stage 1 sleep and in particular when entering or exiting it, I possess some sort of awareness, but it's deranged and limited.
as am i.
the waking from sleep analogy came to my mind also (before you posted it). it's an accurate one, i think. your sleep is governed by your circadian rhythm, which is a non conscious function of your body. consider the state your body is in when awake and the state your body is in during sleep. the transition from one to another is not instant, and your consciousness changes gradually. since it is governed by the body and not the consious mind, it is the body which impedes this consciousness. this is analogous of evolution also, where simpler organisms have a degree of this consciousness (regardless of whether it is ethereal or not).
So, when i elaborated on your framework, i took it further to say that consciousness is directly tied to sensoral capacity/quality.
I want to say, continuing with this metaphor, that only from the perspective of this spark does it seem that there is a gulf between the spark itself and apprehension of its existence (whereby perception can range from clear to indistinct); it is via a singular context that awareness of this context emerges, this singular context also conditioning this awareness's inability to comprehend its origins in full. However, from this background context, one may infer the shape of all possible manifestations of awareness 'prior' to their 'actual' instantiation.
So maybe my hesitation hinges as much on what it means for a phenomenon to exist as it does on what the soul is.
ebola
Don't forget, definitions, by definition, are relative in essence. A thing is a thing when it is as opposed/contrary/compared to other things. In a void, a definition is meaningless. All silliness about demons aside, descartes gives a fairly sufficient defintion of existence. i mean, really, what other choice is there? what difference does it make? there's an experience ofa thinking thing. let's just agree to that and move on.
As for souls, there is a common perception that we a ghosts in a machine, simple drivers to these meat sacks which are identical in character and essence to what is on display for all to see in meat city. This idea of an eternal ego is fundamentally faulty, since we change throughout our lives. The star wars cliche of memory wipes is convenient but nonsense. We pick up character defining traits and dispositions from our experiences in this life, we don't arbitrarily wake up to who we were always and before we were born and will be after we die. You are not a photocopy of your soul, or vice versa.
The reason i questioned the common understanding of what a soul is, is because it is too easy to dispove. Hence the use of spark in the last few posts, which seem to be far more an accurate reflection of what it is that we are, once we shred the lifetime of scar tissue which accumulates and forms our respective characters and egos. The soul/spark is like a ball of chewing gum rolling down hill. It has control over rolling slightly to the left or right at times, but he roll is incessant. The gum picks up dust and grit through this lifetime. We only see these pollutants, and call those parts "me". imo (of course).
Anyway, I think your hesitation is as a result of a faulty framework for the task you're attempting: finding what came before the duality of the issue. But as i noted, the duality is still there. The endeavour is futile.