Oh, it starts a lot earlier than that: the first sentence is poetic and all, but has no concrete meaning. “no greater can be conceived” is not a definition of God, or at least not a very good one. At best (and you’d be stretching for even this), it’s an attribute of God. The concept “Bob is greater than God” is easily conceived of, so it isn’t even true.
Further, “greater” is an adjective: it modifies something, and what it modifies isn’t completely clear, but obviously changes between the first sentence and the third.
The second sentence is equally gibberish: sure, it sounds good, it’s very quotable, like “God is love” and all…but what does “God exists in the understanding” really mean? We see a lot of this on this board: go into any of the religious debates, and you’ll see a bunch of people arguing logic on one side, and a bunch of folks quoting poetic gibberish on the other. Here, the arguer is attempting to take poetry at literal face value.
So given that: “All elephants wear luminous tophats. Obama is an elephant. Therefore Obama wears luminous tophats.” Argument’s valid, but premises (and therefore conclusions) are false.
The uncertainty seems to come not from “existence” but from “presupposing” – i.e., the idea is that that presupposition (of A’s existence) is prerequisite to denial (of A’s existence) – but I don’t see how it follows. Having a conception of something, however vague, is prerequisite to denying its existence in any meaningful way, but conception of characteristics != presupposition of existence.
The argument assumes the definition of God as “the Perfect Being”* – that is why existence is implied, because nonexistence would be a defect at least in comparison to an existent being. Does that allow for more than one? Can there be more than one Perfect Being?
BTW: Who says God is a “Perfect Being” anyway? That ain’t essential to the definition! (To a priest it might be, but not to a philosopher.) An imperfect being could still have made the world – it’s an imperfect world, isn’t it?
Or a simpler example: How many horns does a unicorn have? Obviously, by definition, the answer is “one,” but we have to clarify the meaning of the word “does.” The actual meaning of the question would be “How many horns would a unicorn have if it existed?” I think this is closer to what the OP is thinking.
The OP seems to confuse the definitition of things with things themselves. Defining a thing presupposes the definition of all other things are not that thing. But the existence of a definition of a thing is not the same as the existence of a thing.
All swans are white. You have defined a ‘swan’ as having a property ‘white color’ (not a ‘color’ property that is ‘white’, it is invariant). That also implicitly defines something that has all other properties of a swan except for the property ‘white color’. But the dependent association of ‘white color’ with ‘swan’ says that other thing does not exist.
You don’t have to presuppose the existence of a thing to deny its existence, but you do have to presuppose the definition of a thing to deny it’s existence.
Those who contend that you can deny the existence of asldiujois without presupposing the definition of them are incorrect. There is no logical statement that says something that can be anything does not exist without denying the existence of all things. Denial based on ignorance may work as a political tactic, but not as a logical argument.
Christian philosophers, presumably based on centuries of pondering on Christian theology. Hence my comment about “the existence of a single god”. That argument only works with a) one god, b) that that god is that God.
Not so. There is no definition of a Habalabafabano. It does not exist.
I think what the OP is (mis-)remembering is the problem of non-denoting (or empty) names, as discussed by Russell and Quine perhaps most influentially.
Basically, the problem is with deciding the truth values of sentences that refer to fictional entities, such as ‘Pegasus has wings’. Intuitively, we’d say that statement is true; but if that is so, then there must be something referred to by the name ‘Pegasus’ of which the property ‘has wings’ holds, in some form or another. What, then, are we to make of a sentence like ‘Pegasus does not exist’? If we try to parse it in the same way as the previous one, we arrive at something contradictory – ‘there is something that is referred to by the name Pegasus which has the property of not existing’ seems both to affirm and deny Pegasus’ existence.
This problem is addressed by Quine in his essay ‘On What There Is’, which I suspect may be what the OP was after. One possible resolution would be to say that Pegasus refers to an idea, rather than an actual horse with wings; however, this is somewhat unsatisfactory, since people don’t talk about the idea when they say that Pegasus doesn’t exist (and how can an idea have wings anyway?). One also could quibble about the meaning of the word ‘exist’, about whether or not it is a property, or how it is supposed to apply to fictional entities.
Quine’s resolution, however, is to appeal to Russell’s theory of singular descriptions, developed in his essay ‘On Denoting’. Basically, Russell shows how to use names that don’t actually name – i.e. refer to – anything. In order to do so, one must analyze them as descriptors within the context of a sentence they appear in; so ‘The author of Waverley was a poet’ gets turned into ‘Something wrote Waverley which was a poet, and nothing else wrote Waverley’.
The advantage of this rather cumbersome framework then is that it can be used to talk meaningfully about propositions of existence, without presupposing existence of what is talked about in any way: ‘The author of Waverley exists’ gets turned into ‘Something wrote Waverley and nothing else wrote Waverley’, and its negative, ‘The author of Waverley doesn’t exist’ gets parsed at ‘Either everything failed to write Waverley, or more than one thing wrote Waverley’ – a statement which we can attribute a definite truth value to, without running into the ambiguities previously presented.
Now, all that has to be done is to transform the name of some fictional entity into a singular description (i.e. a phrase that describes one and only one entity) in Russell’s sense: one could, for example, talk about ‘the winged horse captured by Bellerophon’, or, more simply, turn whatever uniquely identifies it into a predicate, and make ‘Pegasus’ into ‘something that is-Pegasus’ or that ‘pegasizes’. These are somewhat ugly, but always possible: every non-denoting name can be turned into a singular description in this manner, and thus, one can speak meaningfully about the subject’s existence; then, one can essentially throw away the scaffolding and conclude that, even if only as abbreviation for a singular descriptive phrase, on was always justified in claiming that ‘Pegasus doesn’t exist’ after all.
If there is no definition of Habalabafabano you cannot form a logical argument about it. Existence is a property of things, and all things have definitions. Logic applies to things. If it has no definition it is not a thing, and using it in logic gives the same result as the square root of a banana.
If there’s no definition of Habalabafabano, then the sentence “Habalabafabano” is meaningless.
What you might be able to say, though, is the following: “Nothing exists which is properly referred to in any language on Earth by the term ‘Habalabafabano.’”
So you’re denying the existence of a meaning of a sentence containing “Habalabafabano” ?
Anyway, the whole question is a lame-ass theist gotcha game, to by used by lame-ass theists who are just busting to tell an atheist: “You said the word ‘God’ when you said ‘God doesn’t exist’, so how can you name something that doesn’t exist unless you believe it does? Checkmate, neener-neener.”
I’m not sure I understood your point, but hopefully the following is a relevant response:
I’m denying the existence of a meaning of any contemporary (well-)written sentence containing the term “habalabafabano.” I’m not denying the existence of a meaning of any contemporary (well-)written sentence containing th term “‘habalabafabano.’” (Count the quotation marks…)
Does that answer your point?
It’s especially lame-ass since it’s a straightforwardly invalid argument, as I’ve explained.