The Bruces: Kit Fine

Banno January 17, 2023 at 21:48 2875 views 11 comments
There's a number of puzzling ideas mentioned in the IEP article, about Kit Fine. Take the following:

Quoting IEP
The scenario involves a person in a universe that is perfectly symmetrically arranged around her center of vision. Her visual field therefore perfectly duplicates whatever is visible on the left to the right, and on the right to the left. When she is approached by two identical twins, she may name each ‘Bruce’. It seems she may refer by name to each. The Fregean can agree only if there is a pair of senses, one for the left ‘Bruce’ and the other for the right ‘Bruce’. But given the symmetry of the scenario, it seems there is no possible basis for thinking that the pair exists.


Are there one, or two, Bruce's? We have left-Bruce and right-Bruce, so they have different senses, but is there one referent or two?

Another nail in the coffin of the idea that names refer in virtue of an associated description.

(A branch from my thread on Fine's article Essence and Modality)





(For the edification of the millennials hereabouts.)

Comments (11)

Banno January 18, 2023 at 21:12 #773787
Consider this new puzzle in contrast to Leibniz's two identical spheres. In Leibniz's example, it is clear that there are indeed two spheres, but we cannot tell which is which. In this new example, what is at question is whether there are one or two Bruces; this is what is not decidable. And this despite there being a clear definite description of each: the Bruce on the left and the Bruce on the right.

In Leibniz example there are two spheres with one description.

In FIne's example there are two descriptions yet it is unclear if there are one or two individuals.

Vera Mont January 18, 2023 at 22:54 #773822
Quoting Banno
And this despite there being a clear definite description of each: the Bruce on the left and the Bruce on the right.


I admit to being philosophically illiterate, but if there were twins on the left and right, shouldn't there be four Bruces?
jgill January 19, 2023 at 04:40 #773922
Quoting IEP
The scenario involves a person in a universe that is perfectly symmetrically arranged around her center of vision.


One Bruce is a kind of mirror image of the other. Not a simple reflection.

Quoting Banno
In FIne's example there are two descriptions yet it is unclear if there are one or two individuals.


I look at a graph on which are defined an x-axis and a y-axis. To the left of the y-axis is the line x=-1, to the right is the line x=1. There are two descriptions in this symmetric world, and two "individuals". But I see how one could say this is the same line in two places.

Stretching the idea a bit, in math a homeomorphism means a continuous transformation of one object into another (doughnut to coffee cup, e.g.) preserving certain attributes. If one Bruce undergoes this process into the other, they are in a sense the same - homeomorphic. In this case they don't even have to resemble each other.

I don't see any deep ideas here. It's simply another word game IMO.
Banno January 19, 2023 at 20:25 #774140
Quoting jgill
I don't see any deep ideas here. It's simply another word game IMO.


The whole of philosophy in a knutshell.

The "deep" question is whether there are any individuals in the world, or if there are only properties, or is it some sort of combination? Frege held that names had both sense and reference, in order to account for the difference between, say, Hesperus (the evening star) and Phosphorus (the morning star).

Whereas most examples are of this sort, with a pair of names share an individual but not a description, here there are either two descriptions and two individuals, or two descriptions and on individual, and no way to decide which is the case.

A philosophical joke.
Richard B January 20, 2023 at 22:55 #774467
Reply to Banno

Does not this scenario presume one individual since it talks about duplicating the source? And if so, in principle, should be decidable.
Banno January 20, 2023 at 23:37 #774479
Reply to Richard B I don't have access to the original argument, but the issue seems to me to be deciding between a universe that is indeed symmetrical and one that merely appears symmetrical. That is, she cannot tell if she is in a symmetrical universe with two Bruces or a universe with one Bruce viewed twice.
Richard B January 21, 2023 at 03:36 #774506
Reply to Banno

Yeah, I need to find that original. That said, maybe I can have a little fun here. Assuming she lives in a symmetrical universe, her everyday experience would be two Bruces.

It would be completely normal for her to see two Bruces, one on the left, and one on the right. Both moving in the same exact way, like every thing else her world. However, I could imagine her wondering. Wondering why two Bruces move the same way on both sides and two Johns move the same on both sides, but most times, the two Bruces move differently than the two Johns. Would she not wonder why this is the case? Would she not seek an expalnation. Then one day, she comes across a mirror, and see a a reflection of herself on one side, and another reflection on the other side. In this case, this reflection moves exactly as she does, on both sides. Would this experience give her insight into an explanation that all is not what it seems? From this imagination, maybe one day, she becomes a scientist, studies the brain, learns how the brain takes in light and forms visual images, and discovers that her brain(brains?) actually form two images. Would she not be able to determine the "underlying reality"?

Richard B February 07, 2023 at 01:37 #779162
Reply to Banno

Pick up a copy of Semantic Relations and the following is the pertinent excerpt of the "two Bruces":

"To this end, let us imagine a universe that is completely symmetric around someone's center of vision. Whatever she sees to her left is and looks qualitatively identical to something she sees on her right(not that she conceptualizes the two sides as "left" and "right" since that would introduce asymmetry) She is now introduced to two identical twins, one to her left and the other to her right, and she simultaneously names each of them "Bruce"; using a left token of "Bruce" for the left twin and a right token of "Bruce" for the right twin. The two tokens of "Bruce" are then always used in tandem so as not to disturb the symmetry. Thus if she uses the left token of "Bruce" to say "Bruce is wearing pink pajama," she simultaneously uses a right token of "Bruce" to utter the same thing. She can even assert the non-identity of the two Bruces by simultaneously uttering the one token of "Bruce" from the left side of her mouth, the other token from the right, and a word for non-identity from the middle of her month.

It seems intuitively clear that she has the use of two names or, at least, the ambiguous use of a single name; and this is something that the Fregean should in any case accept since the name or names can be used to state an informative identity. But what, then, is the difference in sense? By consideration of symmetry, there is no purely descriptive difference in the referents. And this in itself is enough to refute a view that takes sense to be a purely descriptive means of identifying a referent. We can even suppose that she is originally introduced to one person but, seeing him "double," takes him to be two people. Her use of the two names will then not even differ in their reference."
Agent Smith February 09, 2023 at 17:48 #779751
Quoting Banno
That is, she cannot tell if she is in a symmetrical universe with two Bruces or a universe with one Bruce viewed twice.


Hence, Leibniz's identity of indiscernibles rule. Gracias amigo for the profound insight.
Banno February 09, 2023 at 21:38 #779781
Quoting Agent Smith
Hence, Leibniz's identity of indiscernibles rule.


Well, no. Rather if there are two identical Bruces, this is a counter instance. The issue is undecided.
Agent Smith February 09, 2023 at 22:05 #779789
Quoting Banno
Well, no. Rather if there are two identical Bruces, this is a counter instance. The issue is undecided.


:ok: Sorry, I was wrong.