Immutable and supremely simple are descriptors that I like, but I have a little difficulty with the term ‘Ground of all Being’. I ‘came of age’ in the '60s* (but I never grew up 
) and that was of Tillich’s coinage and an impersonal term, I believe, and I soundly reject his neo-orthodoxy.
*I even met Francis Schaeffer once (or twice?), and my wife spent a summer at L’Abri before we were married.
OK, so ground of all being is a loaded term, sorry. What I meant is more like the following (What is Classical Theism? : Strange Notions):
What is classical theism? Classical theism refers very generally to the way most of the great theological and philosophical traditions have conceived God: as the cause of all finite being, the ground of the good, eternal, immutable, transcendent of space and time, perfect, omnipotent, immaterial, infinite, and omniscient.
These very general lines are, of course, construed differently in the various traditions, but the general picture stands out clearly. Classical theism is perhaps most readily explicable by its negations: God is not a being that has come to be, he does not change, he is not limited by space or time, nor indeed limited in any way. God is not an effect, he does not depend on anything more fundamental. God is not a finite spirit flitting about the cosmos like a ghost; he is not a being differentiated from other beings simply by a greater degree of power or knowledge. God’s mode of existence differs from ours as the infinite to the finite.
This view is, by and large, held by the mainstream of the Jewish, Christian, and Muslim traditions; it is the common inheritance of the most influential classical forms of the Western metaphysical traditions; and it may be found by many forms of Hinduism, Taoism, and certain quarters of Buddhism.
That was very graceful retraction, and I concur. 
I guess one of the most apparent differences between classical theism and some modern conceptions is that by saying God is the cause of all being, it also means He sustains all being at every moment, instead of just setting it up in the beginning and leaving it to run on its own.
Expound on the strong nuclear force for us.
See, one of the funny things about the “classical theism” vs “theistic personalism” row is that a philosopher like William Lane Craig would affirm basically everything in that description of classical theism (*) yet he is accused of being a theistic personalist.
(*) Only exception I can see would be that Craig believes God changes in the very minor sense of knowing what time it is right now, upholding the world in existence right now, etc, at each and every moment.
But Craig denies divine simplicity, which many classical theists consider essential to their view: Edward Feser: William Lane Craig on divine simplicity
Hi @dga471, @structureoftruth and @DaleCutler ,
Here’s what Dr. Craig said on the topic divine simplicity in a 2011 podcast:
Yes, there are lots of different versions of divine simplicity that could be weaker. For example, you mentioned the idea, for example, of not having any separable parts. God isn’t made up of a conglomeration of pieces. He certainly has no physical parts. And in that sense is remarkably simple. This is one of the failures, I think, that Richard Dawkins makes in his book The God Delusion in thinking that God must be more complex than the physical universe, when in fact the idea of an immaterial entity that isn’t composed of physical pieces or parts is a very remarkably simple entity. So there are certainly weaker doctrines of divine simplicity, some of which I’d be quite sympathetic to. But this questioner is thinking of this extraordinarily strong Thomistic doctrine that God is pure actuality with no potency whatsoever.
And here’s a link to a spirited discussion between Dr. Craig and Bishop Barron, on the topic of divine simplicity, which is well worth watching:
To my mind, there’s no getting around the argument that God’s nature is necessary, whereas His act of creating the world is contingent, and the necessary cannot be identified with the contingent.
I might also point out that the Catholic Church has defined very little with respect to the subject of divine simplicity, except that God’s essence is simple. The Fourth Lateran Council (1215) refers to God’s “one essence, substance, or nature entirely simple.” However, it says nothing regarding the question of whether God’s contingent actions (e.g. His free decision to create the world) are identical with or distinct from His nature. Nor does it rule out a distinction (posited by the Orthodox) between God’s essence and God’s operations or energies. In my view, Thomists such as Feser (who insists on the strong version of divine simplicity) are trying to put a full stop where the Catholic Church leaves a comma, although to be fair, some Thomists are more open-minded on the question.
How does this fit with the common contention that complex effects require complex causes?
‘Simple’, in this context, is a rather esoteric philosophical technical term, I believe.
Simple magic can accomplish complex effects – at least it can in the eyes of a true believer in simple magic.
So what you’re saying is that God is not simple as the term is ordinarily understood.
Sure. The contention that simple causes can’t have complex effects is wrong. I merely wish to point out that creationists commonly use that claim, implicitly or explicitly.
Most creationist fundamentalists would probably not describe themselves as classical theists, much less Thomists. In fact Aquinas would probably be “too Catholic” of a thinker for them and divine simplicity thought to be too philosophical, abstract, and not “biblical” or personal enough to be applied to God.
As for the relation between divine simplicity and complex effects, David Bentley Hart expresses gives a better idea of what that means (emphasis mine):
One must remember, however, that metaphors are just metaphors, and that the simplicity at issue here is not physical but metaphysical. Among composite things, simplicity is often merely a lower level of apparent mechanical complexity; thus an amoeba is in a sense simpler than a giraffe. Even judgments of that sort, however, are often relative and slightly arbitrary. Considered from a variety of perspectives, one object can be structurally simpler than another in some ways while being more complex in others (at the genetic level, for instance). More importantly, even among physical things one object may have a far greater range of powers than another precisely because it is simpler in structure; a broadax and a guillotine can both perform one very similar unpleasant task, but the former can do innumerable other things as well, not nearly as unpleasant, like cutting down a dead tree or hacking a guillotine to pieces. To speak of God’s metaphysical simplicity is to speak of the total absence of any of those limitations or conditions that might inhibit the power of actuality that he is. Thus, while God is infinitely richer in power than, say, a single subatomic particle, he is in a metaphysical sense infinitely simpler; in him, unlike that particle, there is not even any distinction between essence and existence.
Hart, The Experience of God, pp. 135-136
That makes sense. Now, how can one determine that God is metaphysically simple?
How do you know that our physical reality is not necessary?
Hi @John_Dalton,
How do you know that our physical reality is not necessary?
(1) Do you really wish to claim that everything in the cosmos is simply the way it has to be?
(2) The initial conditions of the universe and the values of the constants are two sets of parameters which give every appearance of being contingent. Are you suggesting that appearances notwithstanding, the values of these parameters cannot be other than what they are?
Let’s unpack first what it means for God to be metaphysically simple. In classical theism, divine simplicity means that God’s essence (the nature of God) is identical to his existence. The way I understand this is that you can’t imagine God having different properties and attributes than what he already has, otherwise he wouldn’t be God, a but a different type of being entirely. To be God is to exist as God.
Now, if God is not metaphysically simple, then he would be metaphysically composite, having his existence differentiated from his essence. Thus, it is possible to imagine multiple instances of God existing at the same time with slightly different accidental properties. This would downgrade the classical God into merely one of a pantheon of gods. To take an example, Zeus and Poseidon are both gods in the Greek conception, even though they have slightly different properties - for example, Zeus uses thunderbolts, Poseidon uses his trident. These are accidental (not essential) properties of being divine in the Greek system. You could imagine Zeus using a trident and he would still be Zeus.
In contrast, the classical God doesn’t have any accidental properties. He just is God, and if you change anything about him then he wouldn’t be the same being. Divine simplicity also entails divine unity: there is no accidental property you can change about God to differentiate him from another instance of him, so God is necessarily one.[1]
Why would we care if God is downgraded to merely one of the multitude of pagan gods? Because if some of his properties could change while still being God, then he would no longer be a necessary being, but merely a contingent one. He would need a cause of his existence, just like everything else. He would not be able to be the Prime Mover (i.e. creator and sustainer) of everything else in existence. He would no longer truly be God, but merely a super-powerful alien being.[2]
Notes
[1] This is also why the popular internet atheist argument that “I don’t believe in Zeus or Odin, why should I believe in God?” falls flat for believers of classical theism, for the God of classical theism is a very different being than Zeus or Odin.
[2] And this makes sense in real life: Thor, who is not the classical God, but a pagan god, has become a Marvel superhero, and it doesn’t feel very jarring. He has great powers but is still limited by the laws of the universe, and dependent on tools and weapons to express his power.
No. I don’t think it matters what I wish to do.
I don’t know if they can. Are you saying you know that they definitely could be otherwise? I don’t think it matters how they appear; in fact the usage of the word “appear” is revealing here. Things are often very different than they appear.
Sorry, but I see all that as being empty words spun out of nothing. You define God as X and show that, by definition, God is X.
You are perhaps not conversant with the several instances in which God has been portrayed as a superhero. Two that I immediately think of are Godman, in Tom the Dancing Bug, and Son-O-God Comics in the National Lampoon.