metaphysical possibility ≠ logical possibility

[dbaltazarful]

Thank you, Urbanelf.

[flexicon1996]

lol "irregardless"

[urbanelf]

@flexicon1996 Did you know that "lol" isn't actually a word?

[DrNSalmon]

The speaker's conclusion is correct, but he does his viewer's a serious disservice by frequently using the phrase 'logically possible' or 'logical possibility' where he means (or should mean) its dual noiton: logical *necessity*. Philosophy is done well only when it is done with care and precision. This is not philosophy done well.

[urbanelf]

@DrNSalmon Where did I say what I did not mean?

[DrNSalmon]

@urbanelf

Starting at around 2:40: "If we look at statements that are logically possible, ..." You mean if we look at statements that are logically necessary, ...

[urbanelf]

@DrNSalmon Actually, I meant what I said. All logically possible statements are derivable a priori.

[jst1g]

@urbanelf (1) Nathan Salmon on youtube????

(2) Just about every professional philosopher who works on logic takes "derivable" to be a synonym from "provable." I assume you meant it a different way. That's why you and Nathan were sort of talking past each other in those previous comments.

[mohamedbongfish]

could you please clarify this point: "the transposition of that is to say that if we can one necessary truth- one metaphysically necessary truth that cannot be derived a priori then it must be the case that logical possibility is not the same thing as metaphyiscal possibilty" and how it follows from what you say before it

[rumpranger65]

I don't really like Kripke's ideas. I think that it seems to be the case that there is a possible world where water is not H2O.

[urbanelf]

@rumpranger65 Well, I would be interested in hearing your thoughts and how that's possible.

[LisaLeftReligion]

Very interesting and favorited for future reference.

[Huesos138]

Kripke was mistaken on a few points. Read up on two-dimensional semantics and you will understand why there is no such thing as metaphysical possibilities or necessities.

[DSBrekus]

Nice argument by contradiction

[WayOfTheBastard]

That was interesting. I think I need to watch it it again. Great stuff though.

[dfthompson]

This seems a bit roundabout to me. "This object is red all over and green all over" is not a logical contradiction - it's representation in PC would be an atomic sentence, such as "Q". But it's a metaphysical impossibility that an object be completely red and completely green (in the same sense, at a single time). Same with "I, dfthompson, am a shoe-lace" (not a thinking shoe-lace - "Oh, no, I'm a shoe lace!" - but an ordinary shoe-lace).

[urbanelf]

Hmmmm...

[urbanelf]

The claim being made is that proper names like dfthompson aren't descriptions of unique objects, so I don't know how your last sentence is impossible. It would be surprising if it turned out that you are a shoelace, but not impossible.

[dfthompson]

I'm not supposing 'dfthompson' is a description, but a proper name and hence a rigid designator. Isn't that Kripke's view? So, given that I'm a human being, it's not possible for me to be a shoe-lace - A world in which neither my body nor my thoughts exists but instead there is a shoe-lace is one in which I don't exist. Remember K's remarks about the wooden table? That individual table couldn't have been made of ice - that would have been a different table.

[bushfingers]

That was VERY interesting and very well explained. Thanks

[migkillertwo]

Very interesting video. So what does it mean to say that some world is "possible"?

[urbanelf]

Thanks! I think of them as concepts, but I think they have to be ones that are not impossible given potentials that are or were present in the actual world.

[drsuessre14]

"Yay," for Kripke! You're right, they're not the same thing at all. However, I was talking to Tom Crisp the other day, and he said certain people - Chalmers and Soames - conceive of logical possibility in very different ways than maybe we're used to. So that's something to keep in mind.

[urbanelf]

You keep giving me more homework. Why?

[drsuessre14]

Sorry. It's there just in case you want look into it. I don't have the time, and even if I did, I wouldn't expect that others would.

[JasperAvi]

Though, I will admit, you did a great job breaking these points down. Took a class on Philosophy of Language in undergrad and it was wildly confusing when not presented appropriately. Thanks!

[urbanelf]

I have to admit, that I do have some questions about how these rigid designators work... and when Kripke gets to his arguments about natural kinds I do have a WTF moment.

Thanks for your compliments.  I had to read the book about 5 times before I started getting it.

[JasperAvi]

Well, one key issue I have with this, is if you find personal identity to be something like Locke's notion. That is, our identity is the conglomerate of memories manifest in a certain particular character as a result. So, if there is some "Avi" in another world, he would need to have all the same characteristics as me otherwise it wouldn't quite designate itself as me. Looking like me wouldn't quite cut it.

So, would something be able to "exist in every possible world", especially a human?

[JasperAvi]

While this whole "rigid designator" business seems appropriate via common sense, there are countless presuppositions about personal identity, classificatory systems, and sentimentality that I'm not sure I'm on board with.

[theowarner]

Thanks... this naming theory is, I think, useful. There is a lot to say about God the proper noun now.

[pfarabee]

I was unsure exactly where you were headed with your argument until the very last part. I guess it's a reflection on how interesting the video was, however, that I watched it to the end.

In all, very good point.

[urbanelf]

Thank you very much!

[TenThousandSubbies]

See, the flaw in your argument is that it is totally unsurprising that Neil Armstrong is a robot built by NASA.

QED

[urbanelf]

NASA hoax ftw.

[LennyBound]

I agree 100 percent.

On a related note, did you know that Quine (who pretty much thought that all talk of modality and possible worlds was nonsense) taught David Lewis (the father of modal realism) at Harvard?

Oh, how far the fruit fall from the tree.

[urbanelf]

Uh oh. I have to confess that I don't know much about Quine or Lewis. I still have more homework to do. :(

[LennyBound]

No worries. I don't know much about them either, but you should really look into Lewis' views on possible worlds if you get the chance.

He believes that all logically possible worlds exist in the same sense that the actual world exists. Consequently, he sees "actuality" as indexical.

[LennyBound]

In other words, he sees the actual world as on par ontologically with any other conceivable world. When we use the word "actual" we are referring to our world, but when individuals in other worlds use the term "actual" they are referring to their world. Both of these utterances are equally "real" in the context of their own world.

Yeah... it's pretty much the most bloated ontology imaginable (no pun intended).