> the whole determines the parts, not vice-versa
Good. I think we can agree to disagree at this point. I try to reach the core premise of viewpoints I don't agree with and I think we have reached it here. I'll try to explain my viewpoints a bit more, but I imagine you'll remain unconvinced. Well, my own overall takeaway is still that I don't need the (personal) God hypothesis to explain the universe (yet) (~Laplace).
I'll say this though. You promised much better arguments than what I had encountered before. I'll admit I found my readings of natural theology pretty interesting. My exposure to arguments beyond using the Bible was only the Kalam Cosmological argument. Many of the ideas in Feser's book and blog articles were a refreshing take, and I had to think a bit about them before I could pinpoint the core ideas and where I disagree. So thank you for that.
> This unity determines the particles' behavior
To me, an empirical study of the universe we sense seems to indicate that the properties of the parts completely determines the properties of the whole. After we have explained the properties of H and O, the properties of H2O are completely fixed and determined. The game of life starts with a simple set of rules and an initial state, and the wonderful patterns that emerge [0] are completely determined after that. Same for the Mandelbrot set. Same for everywhere we look.
My question is, what will help convince you that the behavior of a whole can be determined by its parts? Is being able to accurately predict its behavior by predicting the behavior of just the parts not sufficient? What is left after accounting for the behavior of all the parts of a lion? What is in this essence of lionness that cannot be explained just from the combined behavior of cells?
> The 'laws of physics' are themselves one thing, and not another.
See here we agree. Our universe has a particular set of laws and initial conditions that could have been otherwise. Science takes this as a premise and studies what happened after that. But now take a Laplace's Demon [1] and ask, given the premise, does the universe contain [2] a lion? Answer: yes. Does the universe contain a unicorn? no. Does the universe contain a forum called hacker news where sdht0 and geye1234 are discussing natural theology? yes. I don't see why we need a God who is choosing things to exist or not. We may need God to fix the premise, but everything after that can be God-free. I'll try to explain my viewpoint another way:
> And this implies that certain concepts (lions, gravity) are willed into existence, and continue to be so willed here and now; and certain other concepts (anti-gravity, unicorns) are not.
This is a statement I can agree with, but our takeaways are so different. Imagine a canvas with a lion but no unicorn. If I'm correctly interpreting your concept of "willed", you're saying that there is a God who has two cutout images, that of a lion and a unicorn, and He decided to put the lion on the canvas but not the unicorn. I'm saying, there is a "God" who has a computer program, consisting of just 0s and 1s, which when run on a computer controlling a brush drew a picture of a lion on the canvas.
So I'm just repeating myself now, but regardless of the essences of the objects that inhabit our universe, their existence and behavior is completely determined once the laws and initial conditions have been set as a premise. The question of course remains, where does the premise come from? Here I'm open to possibilities. First Cause. God. Eternal physical laws. Etc. When I read the 5 proofs, that's what I thought, that the books are showing the existence of God at this level. At the edge/beginning of the chain. But you seem to have something else in mind (also as per your other comment) which I don't understand/agree with.
I think you'll agree that given the axioms of mathematics, 2+2=4 is true and not even God can change that. In the same way, as a naturalist, I'm saying that given the laws of our universe (whatever they are) and the initial conditions, lions exist and unicorns don't and even God cannot change that. I'll freely agree that the former is from logic and hence necessarily true. But the later is just from empirical observations. As I said before, if tomorrow God does choose ;) to reveal Himself in a convincing manner, I'll have to change my views completely. Similarly if unicorns start popping in and out of existence.
> I was careful to refer to the concept of lion/unicorn , which exists independently of how particular examples of said concept came to exist.
I'm not sure how to separate those. Doesn't the concept of a lion contain the fact that a lion hunts for food? Which needs biology, chemistry, physics, etc to explain. Or by concept do you mean just the shape? Then is a statue of a lion an actual lion? Like I'm trying to imagine how to explain to an alien from another galaxy the concept of a lion. How can we do that without explaining the entire history of life of Earth, etc?
[0] https://codegolf.stackexchange.com/questions/11880/build-a-w...
[1] https://en.wikipedia.org/wiki/Laplace's_demon
[2] I'm assuming a deterministic universe for simplicity, but it can be sufficiently adapted for the quantum nondeterministic universe by taking about a tree of possibilities and whether any or how many of the branches have some property.