Radical Essentiality of Origins (REO) is the thesis that the complete origins of an entity x are necessary and sufficient to the identity of x. In other words, for any x, if D is a complete description of the origins of x (all the history prior to x, as well as x's initial state), then necessarily something is an x if and only if it has D. In other words, according to REO, origins function like haecceities.
REO has a number of benefits. It reduces the number of brute facts (one doesn't have to explain why I exist instead of someone just like me), it reduces transworld identity facts to REO and diachronic identity, it explains how God knows whom he will create, and so on. It has one cost: it reduces the number of possibilities, eliminating apparent possibilities that people might think are real (like the possibility that I might have lived your life, or had a slightly different causal origin, or that there be two indiscernibles). Moreover, Kripke's quantified modal logic has the deficiency that it has no room for names; but if REO is true, names aren't needed, as we can just use definite descriptions, pace Kripke.
Here's something really crazy you can do with REO. You can rescue something like the definite description theory of names. You say: a name functions as an abbreviation (in a broad sense—I will say a bit more) for a definite description in terms of origins. Thus, "Socrates" abbreviates: "The son of Phaenarete and Sophroniscus, grandson of ..., conceived at ..."
An apparent problem is that it seems that to grasp an abbreviation, you must grasp what it is an abbreviation for. But that may well be false. One can have the concept of the U.N. or of a someone's being a POW without knowing what the abbreviations stand for. (We could explain this datum by saying that there are in fact two words "POW"—one is an abbreviation and the other is a word in the idiolect of those who don't know it's an abbreviation. But the proposal that one can understand an abbreviation without knowing what it stands for is simpler.)
Maybe, though, some user of the abbreviation has to know what it's an abbreviation for. But suppose that Sally wrote down on a piece of paper some definite description, and sealed the piece in an envelope. Then she told me some facts about what satisfies the description, without telling me the description. Maybe it's a riddle and I'm supposed to guess what the description is. So I say: "Let 'D' abbreviate that definite description." I can then use "D" grammatically as a definite description. For instance, if Sally's hints imply that the description isn't (even de facto) rigid, then I can say: "D might not have been D." So I can use "D" in my language. Now, there is a question whether such use is sufficient for counting as grasp. It either does or does not. If it does, then there is no objection to the REO account of names—we just suppose that names function as abbreviations for definite descriptions of the origins, but we don't know what these definite descriptions are. But if it is not sufficient for counting as grasp, we can still say the same thing about how names function. We just have to say that we don't grasp names, though we are able to use them. Maybe only God grasps my name. Or, perhaps, the better thing to do is to distinguish different kinds of grasp. We have a sufficient grasp of a name to use it.
I don't know how this can be extended to fictional names. But Kripke's account of names has that problem, too.
A problem with this theory of names is that there isn't a unique definite description of origins. Conjuncts can be re-ordered, etc. I think to some people this isn't going to be a great cost—maybe a name is an ambiguous definite description (i.e., it's ambiguous which definite description it is), but the ambiguity does not affect extension in any possible world. (Then, maybe a fictional name is an ambiguous definite description where the ambiguity does affect extension?) I don't like that. Another problem this is that I actually think "Tully" and "Cicero" mean different things. To me, this is a very strong, maybe fatal, objection to the crazy REO-based theory of names. But it is a standard view that "Tully" and "Cicero" have the same sense, so to others this won't be much of an objection.
Enough fun for now.