Ah sorry I didn't mean to imply an association, only that both atheists and scientists, from their perspectives, would have no qualms with (and in fact should necessarily accept) an impersonal First Cause.
> we can't understand the full details of how God can will
I'm quite wary of arguments that invoke the "beyond the capability of our minds to understand" clause. But I get it, let's see if A: "we can nonetheless safely say what is not the case: that God lacks will" holds up. I don't think the book makes a good case for A and only offers B, hence my comment.
In general, I think the quibble again is in the definition of the term existence.
* Logical existence: Everything, that is not logically inconsistent, logically necessarily "exists". God has no say here. This is the logical metaphysical landscape, with mathematics and all possible universes with all possible constituents such as tables and unicorns.
* Ontological existence: A small small subset of the metaphysical landscape that we experience with our senses. Here, some things "exist" and others don't. This is what we want to talk about right? What we think about when we ask the questions: where did this come from, who caused this, etc. At least I exist. Thus something exists. Ex nihilo nihil. And thus, a First Cause sustains this something's existence. And the question then is, of the things that do exist, how much control does First Cause have for their existence?
I think your argument above switches between these two definitions, hence the disagreement.
> You could describe the concept of anything in infinite detail without knowing whether that thing exists or existed.
Yeah I read this, but not sure if I agree. That infinite detail would contain its history and details of its components, no? And that would lead to a description of an entire universe, where we can judge whether it makes sense for that things to exist. But anyway, doesn't matter for our present purposes. We can take unicorns to be metaphysically true as an axiom, for instance.
> There is nothing about a lion that makes its existence necessary, and nothing about a unicorn that makes its non-existence necessary.
This is perhaps true for metaphysical existence, but the ontological existence of a lion and the non-existence of an unicorn can absolutely be determined by the physical laws and the initial conditions of our universe. As far as we have probed our senses, the physical world seems to be, with absolute consistency, following a set of laws. All the First Cause has "control" over (right now) is selecting/sustaining what the laws and initial conditions were. The rest of the entire history of the universe is then already logically implied, either deterministically (single line) or probabilistically (a tree), including +lions and -unicorns. First Cause has no say whatsoever.
> Therefore, God is causing lions to exist, caused dinosaurs to exist at one point but no longer does, and has never caused unicorns to exist.
> I disagree with the reductionist account of a table that is I think implicit here
> the parts can only be understood in terms of the whole
This is the core of the disagreement then. "Existence", by which I mean to take this physical universe that we experience with our senses, is empirically reductionist. No God is needed to explain why the Sun rises or why tables retain their form. Each emergent level [0] has a necessary and sufficient cause from the level below it. Tables -> atoms -> quarks -> QFT -> ? -> First Cause. In this sense, First Cause is causing and sustaining the universe. But again, passively, not actively.
Theists obviously disagree with this. But my point is, just from the proofs as the book claims, why can we claim that God chooses unicorn not to exist? All we can say is God chose/is the First Cause physical laws, no? The non-existence of unicorns is implicit in the laws (and initial conditions). No choice needed. And since I have shown an alternative explanation that is consistent with the proofs, a personal God is not a logical necessity, is it? Theist will have to rely on the Bible (etc) for that, not logical proofs.
And also:
> has never caused unicorns to exist.
> If the universe 'burst forth' from God, then anything that could potentially exist, would exist.
Well we don't know! We cannot make any claims about what "exists" beyond our universe. It is absolutely possible that unicorns exist in some other universe. It is possible that the entire metaphysical landscape has ontological existence. We just don't know. And thus these statement cannot be considered true (or false) with any certainty.
[0] Except the origin of our universe and consciousness. The former will ultimately have a brute force First Cause. And the later is an open question right now (a gap).
