Vulcan rotates.
Pegasus flies.
Santa wears a red suit.
Etc. are false WFF where the subject terms do not exist. — Owen
Pegasus exists, is a sensible wff that is false. — Owen
There are no true propositions that have non-referring names or non-referring descriptions as their subject. — Owen
[...] if it's problematic, it's logic that has a problem, not existence. If existence declares that particles are waves or whatever quantum weirdness you care to mention, logic will just have get it's act together about it. — unenlightened
I think we also want a way to talk about fiction (hypothesis, supposition, etc) "in world." So there are two answers, say, to "Does Santa fly in a helicopter?" One is "No, because he doesn't exist," but another is "No, it's a sleigh pulled by flying reindeer." Both have their use. — Srap Tasmaner
But all of this discussion of the truth values of statements about fictional entities, are red herrings (IMO) in the discussion of whether existence is a predicate. — fishfry
Existence is not a predicate because it is something else, namely a quantifier. It's just a matter of getting it in the right logical bucket. — Srap Tasmaner
Sorry, I was never warned of this message, and just accidentally saw it now.If that's your definition of proof, why are you then not a skeptic? — Thorongil
Something seems awry here. The concept of Hobbits exists. Hobbits don't exist (at least not outside of the fictional media depicting them).If someone says, "Hobbits exist," in order for the statement to be meaningful it would have to be about something, but what could the statement be about? It can't be about Hobbits since there are none. Thus it's about the concept of Hobbits. Thus, existence isn't something individuals possess - instead it's a way of talking about concepts of individuals. — Sam26
However, it would then be a contradiction in terms to state that X does not exist. — Arkady
I think Sam was saying that talk of existence is really talk of whether a concept is instantiated. — Srap Tasmaner
The statement is saying that the concept of hobbits has no instances or individuals of which it is true. — Sam26
Fictional things don't exist, but fictions do. — unenlightened
But, exists is not a primary predicate. — Owen
In brief, something like:
existence is not a logical predicate (∃ is not just another φ)
existence can be used as a linguistic predicate — jorndoe
Say, Superman exists, but just isn't real. — jorndoe
And what do you mean when you say that the concept is not instantiated, has no instances? (I deliberately emphasized the verb "to be" in these phrases.) Well, it means that there are no such things, that they do not exist. Oh, wait... — SophistiCat
I think I have a better idea of what you're driving at. A couple of questions/points: what does it then mean to say that a concept exists? That the concept of the concept is instantiated (presumably in one or more minds, or at least in one or more products of minds such as novels, etc., or wherever it is that concepts inhere)?Let me try again Arkady. For example, if I say, "Hobbits do not exist," for my statement to be meaningful, and in particular true, it would have to be about something. However, it can't be about hobbits, as I said above, since there are none; and if it were about hobbits, it would be about nothing. Thus, what the statement is about, is the concept of hobbits, not the subject of hobbits. The statement is saying that the concept of hobbits has no instances or individuals of which it is true. Therefore, existence is not something individuals possess; it is simply a way of expressing something about the concept.
Another important point, is that we must be able to explain the meaning of a proposition, including the subject, apart from knowing whether they're true or false. We also know that statements about hobbits are meaningful apart from knowing whether they are true or false. How is this possible? It possible because we understand the concept, and the only thing we know exists is the concept, not the subject. It can only make sense if the statement is about the concept, and not about the subject.
Moreover, we can coherently talk about the proposition that some X exists, or does not exist, because we are asking whether or not the concept X has an instance in reality. There is no inherent contradiction in the argument. Other philosophers who believed this were Kant and Russell, one being a theist, and the latter an atheist. — Sam26
[...] is confusing for everyone. — Srap Tasmaner
If your point is that this is not an explanation of existence -- the ineffable there-ness of stuff -- I don't think it was intended to be. — Srap Tasmaner
Existence can be modelled syntactically:
P(x) iff ∃x(x=x)
P(x) is true if and only x exists. (x exists iff it equals with itself) — Meta
I actually do believe that concepts inhere in minds (or at least their products), and all else that follows from that: I'm not sure where else they would inhere.I wouldn't say that concepts exist in minds, and I'm not necessarily suggesting that you're saying this, but only pointing this out as a point of clarification. — Sam26
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