To block the inference from
1. Frodo is a hobbit
2. There are hobbits
we can invoke story operators and substitute for (1)
1*. In the Tolkien story, Frodo is a hobbit.
From (1*) one cannot validly infer (2). So far, so good. But what about the true
3. Frodo is a purely fictional character
given that the following is plainly false:
3*. In the Tolkien story, Frodo is a purely fictional character. (?)
How do we block the inference from (3) to
4. There are purely fictional characters. (?)
At this juncture, London Ed makes a paraphrastic move:
Note that 'fiction' just means what is contrived, or made up, or invented. To say that Frodo 'is' a fictional character is simply to say that he is made up, which itself no more than saying that someone (Tolkien) made him up.
Indeed, that is what 'fiction' means, 'pure fiction' leastways. 'Fiction' is from the Latin fingere. So Ed would paraphrase (3) as
3P. Someone (Tolkien) made up (created, invented, contrived) Frodo.
Now if the paraphrase is adequate, then (3) does not commit us ontologically to anything beyond Tolkien. It does not commit us to the existence of fictional characters. Ed wants to avoid views like that of van Inwagen according to which purely fictional items exist. It is worth noting that Ed agrees with van Inwagen about the univocity of 'is' and 'exists.' There are no modes of existence/being for either of them. And for both the one sense of 'is'/'exists' is supplied adequately and completely by the existential quantifier of modern predicate logic. Both are thin theorists when it comes to existence.
But is (3P) an adequate paraphrase of (3)?
I don't think so. If Tolkien made up Frodo, but Frodo does not exist, then what did Tolkien create? A mere modification of his own consciousness? No. He created a character that outlasted him and that cannot be identified with any part of Tolkien's body or mind. Tolkien ceased to exist in 1973. But no one will say that the character Frodo simply vanished in 1973. When Tolkien ceased to exist, his mental contents ceased to exist. But when the writer ceased to exist, Frodo did not stop being a quite definite fictional character. So Frodo cannot be identified with any mental content of Tolkien. Nor could Frodo be said to be an adverbial modification of one of Tolkien's acts of thinking.
I grant that Frodo is an artifact. He came into being by the creative acts of Tolkien and is dependent on Tolkien for his coming into being, and perhaps even tied to Tolkien for his very identity: essentiality of origin for ficta. Frodo is also dependent on the continuing existence of physical copies of LOTR. Frodo is an artifact that came into being and can pass out of being. This makes Frodo a contingent artifact. What's more, Frodo is not merely a content in Tolkien's mind: he can be thought about and understood and referred to by many different minds. So Frodo has a curious status: he is in one way dependent and in another independent.
Now I claim that if one admits that there are different modes of being/existence, one can make sense of this. Fictional characters have a dependent mode of being, but they are, nonetheless, items in their own right. They obviously don't exist in the way a fiction writer exists. But it would be false to say that they don't exist at all. After all, Frodo cannot be identified with a mental content of Tolkien.
So while it is true that someone made up Frodo, as Ed rightly insists, that does not suffice to show that Frodo does not exist.
Ed's paraphrase is inadequate. And so he is stuck with the problem of blocking the inference from (3) to (4).
UPDATE (7/31). I said above, "Frodo is also dependent on the continuing existence of physical copies of LOTR." That's not quite right. If all the copies of LOTR were destroyed tomorrow, Frodo would continue on as a cultural artifact in the oral tradition for as long as that tradition was maintained. But once that tradition petered out, it would be all over for Frodo if there were no physical copies of LOTR (electronic or otherwise) or writings about LOTR on hand. The dependence of abstract cultural artifacts on human beings, their practices and memories, is not easy to understand. We are in the realm of Hegel's objektiver Geist.