When we imagine a red Ferrari, both our physical brain and the non-material image of the red Ferrari still persist. No matter how close we peer into the brain and all it's neurons, we'll never see a tiny little image of a red Ferrari in there. Yet it the image exists nonetheless.
Its almost like a bad joke--let me couch it in a spontaneous koan:
"Now, is this notion of duality which is self-evident merely a construct of your own thinking it so? Or is it self-evident to the rocks at your feet"
"Which mind do you wish for me to use to answer your question: the physical mind, or the mental mind?"
Well I see your point, but I feel that you are probably confusing the image of the red Ferrari (which is nice btw) with the actual mind that see's it. Can you say that the mind is its contents? Would it make sense to say the same about a cup of water? That the cup that holds the water is the same as the water? Our physical brain and the "non-material" image both are concepts that seem to be held inside this cup which remains hidden, unspoken, or forgotten. Can we say that we've answered the question regarding the "what" of a thinking being by referencing the map of externality or the coupling that exists between the bundles of neurons and the world.
Is the fire on the stick the stick or the flame--or both, or neither?
Imagination itself can't exist without the world of objective presence, however it is imagination that lays the foundation for the intelligibility of the same. This two-way coupling between our brain and the world is the world
existingly. There no subject or object in mind, since mind likes to fit itself in the same ontological framework (like a bad SQL insert into a record that has more dimensions that itself!) . I am not disparaging the notion of the mode we call "mental" -- what I am saying is that
it is not a substance--but a process that is inherently already there in the very becoming and being of the universe.
That means there's no "soul" separate from your own objective "becoming" and that your thinking is precisely the working out of the intricacies of the universe (much of which we do not understand--we don't even understand our own questions regarding the same) as a whole. There is no mind, no material--just existence. And it is this existence that we constantly question while at the same time taking its basis--
existentiality or the foundation of existing--for granted.
One more koan...
You said:
Explaining it by arbitrarily giving everything in the universe the ability to think doesn't solve anything
Well you just gave me the explanation--here's a part of the universe telling me that giving the universe the ability to think doesn't solve anything. God of Fire comes for fire!
Ok another example (edit--adding quotes because it seemed rude when I read this later):
"Are you awake? Did you need to think to answer the question? Was that "you" awake before you answered it or after? Are you awake
now?"
"In the morning when you wake up,
what woke you--was that which woke you up also
awake? How can something that is
fundamentally not awake, wake up the sleeping?"
So the question of "arbitrarily assigning consciousness to the universe" here needs further elucidation and consideration.
What I have said earlier is only as arbitrary as the thinking, speaking and writing "piece of the universe" writing these words is right now. What is arbitrary is the fact that we have consciousness, but 99.99999999...% of the processes which keep us going (heartbeat, cellular mitosis, sometimes breathing, sleeping, being hungry, driving to work half-asleep, growing fingernails, hair, skin, fixing and repairing wounds both internally and externally, firing individual neurons, etc...etc...etc) is all out of our immediate mental picture of the universe. All of these processes are a transparent (almost non-existent unless a breakdown occurs) layer that make you
a thinking physical entity in the universe. This--I think--is the most devastating critique of dualism.