Monday, February 28, 2005


Suppose we discover how to make a teletransporter that works like the one on Star Trek. It decomposes your body and your brain and records all the information about them. It then radios a signal to Mars, where another machine uses raw materials on Mars to create a person who perfectly duplicates you. This person walks and talks just like you. It thinks it's you. It seems to remember your life. Would this person be you? Would you survive going through this teletransporter? Or would this person on Mars merely be a copy of you? Would you use such a teletransporter?

Suppose that I kill you, painlessly and without warning, but I introduce a perfect duplicate of you into your life. So no one knows you're gone, because they all falsely believe that the duplicate is you. Even the duplicate thinks he is you, because we gave him a bunch of false memories of your childhood.

Some philosophers think that's exactly what it would be like, if you went through a teletransporter. On their view, teletransportation isn't a way to TRAVEL. It's a way to get yourself killed, and to have a perfect duplicate of you made at the other end. It might not make much of a difference to your family and friends, whether they're dealing with the original or the duplicate. But since you're not the duplicate, you're you, and you'd like to still be around next week, it will make a big difference to you.

Suppose you step into the teletransporter, and it records all the information about your body without destroying you. Then as before, it creates a perfect duplicate of you on Mars. You can hang around and talk to the duplicate on the phone or via webcam. Then after an hour or so, we'll kill the person left on Earth. (Since it would be inconvenient to have two versions of you running around.)

In this case, when there's a delay between the time when the machine records the information about you and the time when your body on Earth is destroyed, it does seem that the person who comes out of the teletransporter on Mars is only a copy of you. So why should things be any different if your body is destroyed immediately after the teletransporter records the information about you? Or if it's destroyed simultaneously? Why should those matters of timing make a difference to whether the person who steps out of the teletransporter on Mars is really you or just a copy of you?

So now we have two different views of how teletransporters work. Which is correct?

Chisholm on Personal Identity

For Wednesday, re-read Chisholm's "Which Physical Thing Am I?" and state which premise he denies in the following argument and explain why he denies it:

1. If ME is correct, then no thing survives the gain or loss of parts.
2. If no thing survives the gain and loss of parts, then I am not strictly identical to any thing that woke up this morning.
3. So, if ME is correct, then I am not strictly identical to any thing that woke up this morning.
4. But I am strictly identical to some thing that woke up this morning.
5. So, ME is incorrect.

Keep in mind that Chisholm understands 'gain and loss of parts' in a more ordinary sense than that of the 'just matter' theorist considered by Sider. Anyone who wants to discuss what they believe Chisholm's response is and whether it is plausible is free to comment on this post.

Staying Alive

Staying Alive is a game of personal identity. You are asked three questions. Your answers are then assessed for consistency and whether you took unnecessary risks. After you finish, there is also a link to some paper on personal identity that I have never read.

For an overview of personal identity that I have read, see Conee and Sider's chapter on personal identity. (Sider's site uses annoying frames so the link is not direct. Click on 'Riddles of Existence' at the bottom of his page and then 'Chapter 1: Personal Identity Over Time'.) The chapter is short and clear and might help to make sense of difficult issues. Also, the objections considered by Sider are interesting, but we will not have time to discuss many of them. This source might be a good one to keep in mind when thinking about a future paper topic (hint, hint).

Wednesday, February 23, 2005

On philosophical amnesia and killing people

Consider the following story, similar to the memory erasing stories from class today. Suppose that this evil guy takes over your personality and goes on a killing spree with your body, all of this happening on Monday. On Tuesday you somehow convince a jury that you have no recollection of the events and therefore are not the same person as the person who went on the spree.

Now suppose you want to kill someone that is still alive. You know that the philosophical amnesia plea works, so you take advantage of it in the following way:

On Wednesday you proceed with the murder and leave plenty of evidence that it was you, but you erase your own memory to where it was on Sunday, before the evil guy hijacked your body. Since you erased your memory you have no recollection of willingly committing the murder. You also don't know about the memory erasing machine or about anything that happened since Sunday.

I now pose two questions: First, are you guilty of the Wednesday murder, and second, are you the same person Thursday that you were on Tuesday and Wednesday?

Sunday, February 20, 2005

I have a quick question to the group: ME would say that there is material that makes up clay, and the same material can make up a statue, as well as any other forseeable combination. Takeover Theory says that the dominant sort that the matter is in is statue. A Cohabitationalist would say that both clay and statue exist, as well as any other forseeable things. So would Cohabitation just be a combination of ME and Takeover Theory [ME + TT = CoH]? Would like to hear what others think about this. I was thinking of this when I was thinking of support for TT over ME.
Now for an argument against ME. I am a Takeover Theory person because I like it the most, I find it the most logical to use. ME will argue that since the matter is there, then the thing exists. Material constitution does not define a thing entirely. A disected worm in a highschool biology class might still have all of it's parts, but that is not the same worm it was when it came out of the ground. I am interested to hear an ME reply.

Friday, February 11, 2005

An Epistemological Note

In this course, we are investigating metaphysical issues: What is the nature of the relationship between a thing and its parts? What is the nature of the relationship between a person and its parts?, etc. An entirely different question, which we are not investigating, is epistemological: How do we know about things and their natures? Though the latter question is entirely different from the former, it is not completely unrelated.

I get the impression from some that the only good answer to the epistemological question is that we know that p just in case p is proven, where this requires something very strict, like deducing p from purely logical truths. This raises many delicate issues in epistemology that are outside of the focus of this course (but well within the focus of Professor Feldman's class, 'Theory of Knowedge', for those who are interested). In this post, I want to give some reason for thinking that requiring logical proof in order to accept p is too strict. I'll conclude with a bit about how I see the role of arguments and proofs in our metaphysical investigation. This is by no means a compulsory way to view the role of arguments, but it is one that seems compatible with a less strict account of what it takes to know that p.

So, to be clear, here is the Strict Epistemological Thesis (SET):

(SET) S knows that p only if S deduces p from purely logical truths.

Here's an objection to (SET):

1. If SET is true, then if a car is bearing down on S at high speed, S does not know that there is a car there and that S is in danger. (This proposition, I assure you, is not derivable from solely logical principles. It requires something like seeing that a car is there, which is no truth of logic.)
2. If S does not know that there is a car there and that S is in danger, then S's dodging the car is irrational. (The idea is that there is a connection between what we know and what we do, and what we don't know and don't do.)
3. S's dodging the car is not irrational. (We would think someone who saw the car but just stood there is crazy or otherwise mentally unfit.)
4. So, SET is false.

I think a proponent of SET should deny (2); S may have a justified belief that there's a car and S is in danger. And having a justified belief is a sufficient basis for rational action.

This objection seems fine to me. But note what it concedes. If this reply is correct, we don't need deductive proof from logical premises to have a justified belief that p, and having a justified belief is sufficient basis for rational action. So, for instance, I could be justified in believing that tables exist, and this allows me to rationally do stuff like put things on tables and say things like 'Tables exist'. In other words, if some proposition is justified for us, then it is rational to accept it. And being justified does not require strict proof.

The moral seems (to me) to be that, even if SET is true, it is rational to accept what we have justification for, and justification requires something less than proof. Consider, for instance, how a proponent of a related view, (SET'), would reply to (1-4):

(SET') S has justification for p only if S deduces p from purely logical premises.

It's puzzling why a proponent of (SET'), if she really accepted her view, would dodge the oncoming car.

So I think that all of this shows is that, regardless of the status of (SET), (SET') is false. But all we are after in a metaphysical investigation is to be justified in accepting some one metaphysical account versus the others. This, in turn, only requires that (SET') is false.

Sophisticated sympathizers of (SET') may have noticed that the above argument against their view does not meet their standards for proof. After all, though the proof was deductively valid, its premises were far from logical truths. Thus, a proponent of (SET') might maintain that this argument does not compel her to abandon her position.

I supect that, if a proponent of (SET') is sufficiently committed and resourceful, there are no arguments that an opponent of (SET') could supply that would force her to abandon her position. But there are two different aims we might have when thinking about (SET'). First, we might aim to provide arguments that a proponent of (SET') would accept which would show her view is false. Second, we might aim to argue that those who are "shopping" for a view of justification or knowledge that (SET') is not the way to go. Though I think the first aim may be impossible, the second may be attainable.

G. E. Moore, an analytic philosopher who wrote early in the last century, argued as follows:

1. Here (holding up one hand) is one hand.
2. Here (holding up his other hand) is another hand.
3. If (1 and 2), then there are at least two hands.
4. So, there are at least two hands.
5. If (4), then there are at least two things external to our minds.
6. So, there are at least two things external to our minds.

(6) is a conclusion that proponents of (SET') cannot accept, since (1) and (2) are clearly not truths of logic. A proponent of (SET') might argue like this:

1. If S is justified in believing p, then S deduces p from logical truths. (statement of (SET'))
2. Alleged justified belief in hands, cars, etc. is not derived from logical truths.
3. If (1 and 2), then no one is ever justified in believing that they have hands, that there is a car, etc.
4. So, no one is ever justified in believing that they have hands, that there is a car, etc.

What Moore wants to know is, if he is not justified in accepting his premises, what justifies the proponent of (SET') in accepting hers? Suppose we are shopping for a view and we are undecided on whether Moore's way or (SET') is the way to go. Moore asks, how can it be more reasonable for you to believe an abstract philosophical thesis like (SET') than it is for you to believe his premises? Common sense compels us very strongly to accept that there are hands, cars, etc. This is not the case with (SET'). So if we are shopping for a view, we should prefer Moore's to the more skeptical alternatives.

The upshot seems to be that, if Moore is correct, (SET') is unacceptable. But if that's so, there's room for us to have justified beliefs in things that are not established solely on the basis of principles of logic.

I'll end by explaining one way in which a Moorean might view the role of epistemology in our metaphysical investigation. We start, at the outset, with our common sense and the dictates of science. (It's worth noting, very briefly, that science, all by itself, does not imply that there are no tables, etc. One route to this view is Ontological Fundamentalism, which is explained and evaluated here.) We are, by and large, justified in accepting what common sense and science tells us. In many cases, our reasons are very strong, though they do not constitute a proof.

We want to find out the answer to some metaphysical question, such as 'What is the nature of the relationship between an object and its parts?' Insofar as possible, we should try to accept a view that comports with our pretheoretic conceptions. To help us focus our investigation, we consider some problems about the relationship between an object and its parts. We want the answer to our metaphysical question to adequately address these problems while preserving what's right about our pretheoretic conceptions. So we consider several views and arguments for and against them. The idea is that the view that fares best against objections and otherwise meets our criteria is the one we should accept.

This turns out to be enormously difficult, since it involves discovering the very best arguments for and against the views. But even if we do not decisively resolve the issue, we gain the benefit of a better understanding of the relationship between objects and their parts. (This point generalizes far beyond metaphysical investigation; what is offered here is one picture of how we might view the project of understanding the way the world is which is the common goal of all disciplines, not just philosophy. On this picture, the sciences, for instance, primarily differ from philosophy only in offering empirically based arguments.) No deductive proof of any view is required or expected. No deductive proof from purely logical principles that an objection is sound is required or expected. Rather, the arguments for and against give us an idea of what we should believe "on balance". So if a view implies (for example) that there are no hands, that is a cost of the view, even if it does not show (in the sense of (SET')) that the view is false. What we need to figure out is which costs are worth paying and why.

This approach is broadly accepted by analytic philosophers. That does not mean that you should accept it, of course. To re-emphasize, the point of this post is to give one picture of the role of arguments in metaphysical investigation and how this relates to the epistmological question of what we should believe. As with any view, there are alternatives. If you are attracted to an alternative view, it may be helpful in developing your view to see where, exactly, the Moorean view goes wrong and why. And if you are attracted to the Moorean view, it is also fruitful to try to see how one who rejected it would argue against it. A fundamental presupposition of this course is that, by carefully considering our views and the views of others, we arrive at more well-considered views and a better understanding of the subject of those views.

Wednesday, February 09, 2005

Something strange

One of the most confusing aspects of ME is this. According to ME, if a thing ever has, does or will exist, it exists at all times. This is hard to grasp, and of course it is tough to grasp. I hypothesize, based on outside reading (Jason will get this soon) that we as three dimensional creatures only affected by the fourth dimension do not have the capacity to understand ME.
Think about it in terms of mathematical dimensionality. We are 3 dimensional creatures, yes? when we look at a two dimensional object, like the painting The Last Supper, we can see everything that exists within that painting at once. we see all the people, that halo thingy, the food, the window, etc. We see it all, because it's flat.
However, go inside one of the disciples minds for a moment. They cannot see much of their surroundings. From a 2 dimensional viewpoint, their "flat," 2 dimensional view of say, the dude at the end of the table is obstructed by someone sitting in the way. however, that doesn't mean that people sitting at the end of the table dont exist. Now, throw time in, pretend it's a Movie Last supper. the guy in the middle of the two disciples moves, and the first disciple says, hey, that guy at the end of the table just appeared from nowhere. We, as 3 dimensional creatures, know that that guy at the end of the table was always there, but the 2 dimensional dude did not. This argument can follow for a 2 vs 1 dimensional world too.
We are described by 3 spatial dimensions and some would say one temporal dimension. It seems more than likely that you can extrapolate the previous situations to ours, that point of view matters. In class we discussed perception as being totally key to TT, so mathematically speaking, it would take infinite perception to grasp all perceptions possible at once. But, just as the 2 dimensional disciple could assume there were more people "over there," based on prior knowledge, So, I think can we.
Basically, I'm saying that something hard to grasp isn't necessarily false.
CITE: Michio Kaku.

Tuesday, February 08, 2005

Thought about ME

Ok, so our conversation about what actually exists when according to ME left me a little confused and highly doubting the ME theory in general. I still maintain, that according to ME, one partical will exist in many objects at any point in time, and therefore, infinate objects have the potential to exist at the same time using some of the same particals. However, due to the nature that an object would need all it's particals to be complete, there is probably a finite number of objects one partical could belong to at any one time, but still, how does that work? Also, I'm confused, according to ME, if you take away part of an object, like you rip off a scrap from a piece of paper, how exactly does that piece of paper change? Does it still exist but in a different form? Anyway, the thought that at anyone time a finite or infinite (not sure which) amount of objects 'exist' was rather disturbing, esp. when they 'exist' even if you're in an empty room or something. Well, I found that disscussion we had at the end of class worth posting about, so maybe we can continue it here, let me know.

Monday, February 07, 2005

Takeover Theory

Perhaps some food for thought on support for the takeover theory.

I'm thinking that people WANT to believe the ME theory, because it sounds ordered, but I have my doubts as to whether people actually believe it. Because if you actually believe a theory, you would live your life by it. Thus I don't think people actually believe ME too greatly, and here's why:

If I go into a car dealership and want to buy a new Ford (well, make that a Subaru or something more reliable), I'm going in to buy a car. I'm not going in to buy all the particles that makes up a car. Surely if I recieve a pile of metal which contains all the pieces of a car, I'm not going to say, yes that is what I'm paying for. I am paying for 70 billion particles that compose a car. I say no, give me my $15,000 back. When I want to buy a car, I want to buy an object of a particular sort. I want it to have an engine, run cleanly, and get me from point A to point B. If I destroy those characteristics, by ME I havent destroyed the car, merely those properties. The car still exists as the same object. But thats not how I live my life on a day to day basis. I like the sound of ME, its all very ordered, but I think its all just mind games.

Thats my story and I'm sticking to it.