Here's a question indirectly related to the doctrine of the Incarnation, but I won't explain the connection until after asking the question, in case that will encourage unprejudiced reflection on the question.
As background for the question, assume that individuals belong to natural kinds, and that properties can be essential to both individuals and kinds. In addition, an individual can belong to a kind either essentially or accidentally.
The question has to do with which properties are displayed by individual members of a kind, and I'll first note some relationships that don't hold here. Suppose P is essential to kind K (such as animality being essential to humanity), and V is a member of kind K.
First, P can be essential to K without being essential to V, since V might not be essentially a member of K.
Second, P' can be essential to V without being essential to other members of K, since P' might be the property of being identical to V.
Third, P' can be an essential property shared by V and other members of K without being essential to K itself, as when P is a logical construct out of individual essential properties (e.g., let P' be: being identical with V or V' or V'').
Suppose, then, that, as before, V is a member of K, and that P' is uniquely essential to V (i.e., it is not essential to any other member of K), but that it is not uniquely essential in virtue of being logically guaranteed to be exemplified by only one individual (as a self-identity property is) nor is it a logical construct out of such (such as being identical to V or some fictional entity).
Finally, the question: should we expect, in general, that in such a case it is a general feature of kind K to be open to being P', i.e., that, in general, other members of K might have been P', though not essentially? Or are we not entitled to any predisposition in the matter, thinking it equally likely that there could be a logically shareable essential property, not shareable by logical construction from uniquely individual essential properties, and yet it be impossible for any other member of the kind to have the property in question?
Here's some examples to try out one's inclinations on that relate to the Incarnation: If V is essentially sinless, should we expect other members of K to be capable of being sinless (though not capable of being essentially sinless); if V is essentially omniscient, should we expect other members of K to be capable of omniscience (though not capable of essential omniscience, and perhaps only derivatively omniscient, by learning all truths from another being who knows them); if V is essentially everlasting, should be expect other members of K to be capable of existing at all times?
Here are some examples that puzzle in the opposite direction: being essentially omnipotent (but maybe only because there is some temptation, albeit mistaken, to think that there can only be one omnipotent being); being essentially eternal, in a sense intended to contrast with everlastingness; being essentially incapable of being annihilated; etc.
Suppose you restrict property F to those that are not uniquely essential and restrict your domain to members of K. Your question seems to be whether it is true that (1).
1. [](Ey)(x)([]Fy --> >Fx)
That is, necessarily, if there is some member of K that is essentially F then every member of K is possibly F. So, the question comes down to this: could some member of K be essentially F and another member of K be essentially not-F? Here's one: the property of necessarily existing. That is a property such that anything that possesses it, possesses it essentially. So no contingently existing being is possibly a necessarily existing being and there are many necessarily existing beings: God, numbers, propositions, etc.
Mike, (1) is a claim that I'm interested in, but it is pretty obviously false, and the example you give works just fine to show that it is false. Let's restrict the property F further, so that it is not itself an essential property.
Even then, I don't think (1) is true. My question is more about how we think things are likely to go: should we expect it to be true in the usual cases, or should we be indifferent?
If it were always and everywhere false, then it appears to be too easy to resist the claim that a given entity can't be an instance of two distinct (but obviously incompatible) natural kinds. For example, being gold and being an abstract entity: argue that all apparent essential properties of each are only common properties of things that are members of only one of the two kinds, and that since (1) is always and everywhere false, a thing can be both gold and an abstract entity.
So we don't want (1) to be false for every value of F. One way to proceed is to try to restrict F enough so that (1) is true, and that's an interesting approach. I wasn't thinking of trying that, however; instead, I only wanted to ask whether we should expect most instances of F, suitably restricted, to yield a truth.
Under the restrictions I didn't find it obviously false at all. Most properties that look like they'd be falsifying instances turn on controversial metaphysical claims. For instance, I feel pretty certain that there is no world in which I am even contingently omniscient. But I have no idea--not the slightest--how to convince another non-divine human that this is also true of them. Further, at the moment I cannot name two other properties that obviously falsify (1). Properties, that is, that don't make controversial metapysical assumptions. Can you?
Richard Gale might be prepared to do so. He did once challenged P. van Inwagen to a "modal intuition bowl". Maybe he has better access to the realm of possibilia.
Mike, here's a couple cases where an instance of (1) looks true. One is where the property F is sinlessness (assuming that God is essentially sinless), and another is everlastingness (assuming God is essentially everlasting). Other cases where it is false include being the sole creator of everything distinct from oneself and transcendence.
I'm more sanguine than you about omniscience. I don't see why God can't create you with innate knowledge of all truths.
Jon, I feel like I'm playing two dimensional tennis. Anyway, here are the examples you offer,
". . . cases where it is false include being the sole creator of everything distinct from oneself and transcendence".
But if F = being the sole creator of everything distinct from yourself then only one being could have F essentially. That is contrary to one of the restrictions. It is uniquely essential and contructed from the property of self-identity. It is the property of being such that everything that fails to be identical to me is created by me. If F = transcendence, then (1) is falsified only if there is no world in which I am transcendent or no world in which I am both transcendent and immanent. Are there no such worlds? I have no idea. Since I have no argument for it, I take this version of F to include a controversial metaphysical claim.
You're right, Mike; I wasn't intending to abide by the restrictions (but it would have been nice to point that out!). On the account of transcendence I favor, it is logically equivalent to something involving being the sole creator of everything distinct from oneself, so it would fail to pass the restriction test too.
But I don't want to skirt discussion of the matter just because it relies on controversial metaphysical assumptions. I *want* something like (1), suitably restricted, to be true--I think it offers a basis for a more plausible defense of the possibility of the Incarnation than does the mere assertion that the properties we thought were essential to ordinary humans are merely common properties that are not essential. If something like (1) is true, then we can call the collection of properties in the final consequent of (1) the "divine spark" in human beings. If there is such a divine spark, then we have a plausible story to tell about how it is possible for an individual to be both God and man, even if that possibility obtains only for one individual. Do you see what I'm after?
Yes, I think I see it. But it must matter that the incarnated being has two natures. Does something unfortunate follow from the suggestion that it is his divine nature that is, say, essentially omniscient, not his human nature? Maybe that doesn't make sense.
Well, it has to be the individual that is essentially omniscient, but I would say that it is in virtue of the divine nature that he is essentially omniscient. The question is whether there is a divine spark of these perfections in ordinary humans. The alternative is a picture of the Incarnation that looks very much like the example I presented as to how to defend that a single thing could be both gold and an abstract object.