Mitchell, The difference between your thinking and mine is small.
You believe the spiritual things exist without needing a living organism. But I think a living organism is necessary to help them exist or function.
The below is what I think.
(It may not be accurate in terms of science. But I tried to find the right thinking that would not be at odds with the known facts.)
If we try to explain the behaviors or phenomena of
Physical things, which serve no purpose (or we haven’t discovered their purpose)
Their behavior can be explained by natural laws.
Simple organisms, which have a purpose (to serve themselves), but do not have the need or urge.
Their behavior can be explained by A + the purpose of serving oneself including reproduction + DNA/RNA, etc.
The organisms are no longer pure physical but have sensors and reflexes, and spiritual things arise and they can have urges or unbalance to push them to actively look for food and avoid danger. But they can’t remember like human. They can’t be trained. For example, a worm.
Their behavior can be explained by B + reflex + urge + a spiritual thing (or mind, soul).
The organisms have something working between what they sense, feel and what they do. They do not just react by reflex. They can decide. They can remember and recognize something, can learn and be trained. They have emotions. But they can’t have theories. They may possibly have simple but not complex imaginations. For example, a leopard approaching its prey.
Their behavior can be explained by C + decision + possible imaginations or expectations to complete a task.
A few animals can make and use tools. They can have more complex imaginations and can think.
Their behavior can be explained by D + some intelligence.
Decision making plays a much more important role in human life than in an ape’s life. Humans also suffer more distress from their own imagination and wish.
Humans can have the ability to make theories based on facts, can have much more complex imaginations, make decisions based on their knowledge or belief, can decide what to pursue, deal with their emotions, wishes, etc. which can’t be found in any other animals.
The non-social human behaviors can be explained by E + a powerful mind and the need to deal with the “side-effect” coming with such a powerful mind + finding solutions to the problems they face in their life, + the personal choice of the way of life, etc.
The social human behaviors can also be explained but in a different way.
So the spiritual thing appears not the same in a worm as in a human. But is it because the same thing in different states? Probably.
And, if the existence of spiritual things is independent of the living bodies, then why does their performance vary from species to species? If the spiritual things have to work with the nervous system, then how do they work together?
Until we know how do they work together, everything we say now is just a guess.