Prove that red is a color

The irony, that seems to escape the OP, is that this whole statement is not a logical proposition. It is, itself, a definition! It is neither true nor false. Which is, itself an unprovable statement because it is a definition upon a definition.

But gosh, it sure is exciting for some reason. I respectfully suggest you stare at your navel for 10 minutes until your mind settles down.

This is fascinating, and gave me something to ponder while I suffered from insomnia, yet AGAIN last night.

Could someone point me to the original thread?

CanvasShoes, Don’t say I didn’t warn you. . . .

Daniel

The argument that definitions are not a matter of proof? On the contrary, that is exactly what he has solidly attached himself to. Show me a text in mathematics or logic or science or purt near anything else that “proves” a definition. Otherwise, shut up.

Sadly for you, Lib, I’ve got more options than that. Just as you have more options than:

  1. Continuing to throw a tantrum;
  2. Showing me a definition in formal logic containing the phrase, “This entity is one about which the sentence, ‘this entity exists,’ is true”; or
  3. Shutting up your own self.

Daniel

Well, why don’t we all just throw out our dictionaries, then? I’ve got Webster’s Unabridged, and they haven’t proved a damn one of their definitions.

Because to the best of my knowledge, none of Webster’s definitions say (this entity exists, by the way) in them. Webster’s definitions don’t exclude a possible conclusion about their entities’ existence, as McHugh’s definition of God does in excluding the possibility of contingency.

Daniel

Because, unlike this discussion, a dictionary is useful, instructive, and helps me to meet intelligent women.

So, DanielWithrow, am I to understand that defining things is all hunky-dory so long as we don’t do anything with them?

No, defining something is perfectly okay as long as we recognize the limitations of the definition and don’t try to give it more weight — more “reality” — than it deserves. Labeling and categorizing things is fundamental in human psychology; we can’t help it. However, the more we learn, the more we understand that these definitions tend to get blurry at the edges.

Our conception of animals as being divided sharply into discrete species, for example, isn’t particularly valid given recent revelations about the general fluidity of biology. That doesn’t mean that an overarching unspoken agreement to pretend otherwise isn’t useful for creating a common vocabulary with which we can discuss said animals according to some sort of conceptual consensus.

It’s sort of like how Newtonian mechanics is useful at the macro level, but doesn’t hold true all the way down to the subatomic. By strict intellectual rigor, you can make a case that Newtonian mechanics is therefore “useless” and that its definition should be thrown out, but reasonable people recognize that suggestion as the foolishness that it is.

What’s in a definition? A rose by any other definition would smell as sweet. Unless thou is defining thine Aunt Rose, who smells overly of lilacs.

**“Thou is”??? **
Sir, it is “thou art”
Bone up on your Elizabethan English or get out of the Pit.

D’oh! er, I mean: Zounds!

Yes, and ultimately nothing can be proven. Continually asking for proof eventually descends into sophistry. It is a rhetorical flourish that can be used to demolish any argument IF you believe that pure reason and reality are the same thing.

It’s like a child asking “Why” after every explanation you give.
“Why is the sky blue?”
-“Because the atmosphere refracts blue light more than other colors”
“Why?”
-“Because sunlight contains a variety of colors, and the quantum structure of the molecules in the atmosphere interact with photons in such a way as to send blue light to the ground”
“Why?”
-“Because the energy level of blue light interacts with the quantum levels of molecules in H20 such that light is absorbed and reflected at a different angle than other colors”
“Why?”
-“Because of quarks, strings, and Heisenberg”
“Why?”
-"…here’s a gummy bear."

Sooner or later you run out of answers, but you still have to get dinner ready or you’ll starve and die.

Methinks “Zounds” is Victorian. Say you instead “True, t’is true. I do well thee mark, sire.”

This definition seems to exclude a bazillion conclusions:

— Webster’s Unabridged

Erislover, I have no idea if that’s what you’re to understand. Whether or not it is, it has nothing to do with what I said.

I said that a definition of an entity cannot assume a conclusion about the truth of an entity.

Help me out here with some examples. I want to determine whether Frank exists, and whether Julia exists.

First, let’s define Frank:

  1. Frank is a bird.
  2. Frank speaks sixteen languages.
  3. Frank is an internationally-recognized sex symbol.
  4. Frank is a being about whom the sentence, “Frank exists,” is true.

Second, let’s define Julia:

  1. Julia is ferschnuckly.
  2. Julia is a being about whom the sentence, “Julia exists,” is true.

Now let’s deal with Frank. I’d suggest that it’s pretty unlikely there’s any bird who speaks sixteen languages and is an internationally-recognized sex symbol. Such a being doesn’t exist. However, if such a being doesn’t exist, then it doesn’t match the definition of Frank, because part of Franks definition is that Frank is a being about whom the sentence, “Frank exists,” is true. So how do we determine whether Frank exists?

Finally, let’s deal with Julia. I’ve got no idea what ferschnuckly means, so I can’t tell how that impacts the existence of Julia. However, in order to actually be talking about Julia and not some other being, we must be talking about a being about whom the sentence, “Julia exists,” is true.

Have I therefore proved that Julia exists? If I’ve proved she exists, can I not use the same method to prove that Frank, the international sex-symbol polymath bird, exists?

I believe that the problem is with including the characteristic, “X is a being about whom the sentence, ‘X exists,’ is true,” in the definition: the existence a being so defined cannot be properly evaluated using a true/false logic system. Similarly, a being whose definition includes the characteristic, “X is a being about whom the sentence, ‘X is contingent,’ is false,” cannot properly be evaluated using modal logic, for the same reason.

These are highly peculiar definitions; I’m sure you recognize that no dictionary defintion includes that peculiar little phrase in it. It looks to me like a magician has discovered a new trick, one that fools even himself; if you examine it closely, however, you’ll discover that it’s just a trick.

Daniel

Yeah, well, nothing’s perfect.

Daniel

Daniel, assuming that something exists in some possible world—that is, to speak in non-modal logic words, assuming that something is possible—is hardly uncommon and I don’t see the problem with it in the slightest. The distinction between “possible” and “exists/ is the case” seems so clear to me that I must admit I cannot even begin to explain why it is reasonable to say such things. I realize the objection you have centers more around the hidden “ontological proof” buried in the union of the two assumptions of Tishammer’s modal proof, but really, the using a working hypothesis that something is possible actually exists is, I would expect, not foreign to anyone. This is my beef here.

No one but Vorlon and similar detractors seem to conflate “possible” with “exists” in any other context, so I don’t see why it suddenly makes an appearance here. If so, it certainly isn’t there because of the semantics of modal logic.

Under normal circumstances, I think that’d be okay. Imagine we’re trying to prove that some human beings are capable of eating some apples. Obviously, we’ll need to define “human being” and “apples” in order to create this proof; we’re also justified in assuming that both human beings and apples are possible.

But if we’re trying to prove the existence of apples, then we cannot define apples in such a way that they exist.

I think something similar is going on in McHugh’s proof of God’s existence. In Modal Logic, when you’re trying to prove something’ existence, you’ve got three possible outcomes: it can exist necessarily, it can exist contingently, and it can not exist. When you’re trying to prove something’s existence, you can’t define that something in such a way that one possibility of existence is removed before the proof begins. If you do so, modal logic is hamstrung, and cannot evaluate teh thing’s existence.

It could conceivably do other things. Modal logic could use McHugh’s definition of God to evaluate the question of whether God could microwave a beef, bean, and cheese burrito so hot that He couldn’t eat it. But I don’t think his defintion is useful when the question is whether God exists in the first place, because it artificially narrows the system’s possible outcomes.

Daniel