A Skeptical Dialogue

Sophia: What is this?

Pratt: What is what?

Sophia: This. (Points)

Pratt: The table?

Sophia: Why do you call it that?

Pratt: What, table?

Sophia: Yes.

Pratt: You’ve got to be joking.

Sophia: No, really, for the sake of the argument, play along.

Pratt: I don’t see the purpose of this.

Sophia: C’mon, it’ll be fun.

Pratt: You’ve got a sick idea of fun.

Sophia: Just do it.

Pratt: Alright then. (Takes a breath)

Sophia: Why do you call this (points again) a table?

Pratt: Well, because it looks like a table.

Sophia: But how do you know?

Pratt: I’ve seen enough tables to know whether something is or isn’t a table.

Sophia: That doesn’t really answer the question.

Pratt: This is ridiculous.

Sophia: Why exactly does it look like a table to you?

Pratt: Well, tables usually have four legs and a flat surface, but I suppose there could be any number of legs. And this thing resembles what I described. Look (points). Legs and surface.

Sophia: But why is that what constitutes a table?

Pratt: Hm. (Pauses for a moment). Because that’s what I learned?

Sophia: But no one told you that a table is four legs and a flat surface, or any number of legs for that matter.

Pratt: Sure, but we are all told what is what when we’re learning language as kids.

Sophia: Right, maybe someone would point to something and call it a name.

Pratt: So that’s it then?

Sophia: Not so fast.

Pratt: Ugh.

Sophia: That only explains how you learned specific instances of things. What about when you see a new object that kind of looks like the previously named object, but is a little different?

Pratt: Beats me. Seems like we just make inferences. Like, they called that one a table, and this one kind of looks like it, so then you call it a table and you’re either successful in your communication or unsuccessful. Rinse and repeat.

Sophia: Ok, forget the theory. Tell me your specific experience. When you say that this is a table, do you consider it being anything else?

Pratt: Hm. I think it depends on my goals. If I’m looking for somewhere to place a cup or some books, it appears to me as a table. But if a light goes out and needs to be replaced, it may then appear to be a stool because I can use it for that function. But I wouldn’t call it a stool. I would say that I’m using the table as a stool.

Sophia: Now that’s interesting. Why wouldn’t you call it a stool?

Pratt: Because its primary purpose is to be a table, not a stool.

Sophia: Primary purpose, huh? I think you know what I’m going to ask next.

Pratt: How do I know what its primary purpose is?

Sophia: Exactly.

Pratt: You really don’t let up.

Sophia: Nope.

Pratt: Let’s see. I know the intention it was created for? But that doesn’t help if you don’t know why someone made what they did. You’d have to be there to ask them or they’d have to communicate it somehow. I think you can infer something’s primary purpose by the context it's situated in. Like, you see four legs connected to a surface and on the surface are some cups and books, so from that, you determine that it’s more likely a table than a stool. A stool probably wouldn’t have stuff on it. And it might be in a position which indicates that people frequently use it to reach some higher place. What do you think?

Sophia: Surely something’s primary purpose can change, it’s not fixed by whoever made it. Maybe the intention for a thing was to be a table, but now it's only used as a stool. So wouldn’t we say that the thing’s primary purpose is to be a stool? Anyway, let’s set that one aside for now. I’m intrigued by your other point. Essentially, you’re saying that we’re all walking around making educated guesses about what things are, all the time?

Pratt: Well, when you put it like that, it sounds kind of silly, but yeah, I think so. Take this example, you’re walking through a store and pass by a mannequin, but you think it’s a person, so you say, “Excuse me.” One of two things can happen. You either realize that it’s a mannequin or you don’t. The fact of the matter is that it’s either a person or a mannequin. It can’t be both. Depending on the circumstances, like if you’re in a hurry, you may never realize what it actually was.

Sophia: Do our senses deceive us?

Pratt: Sort of. Think about it this way: you give someone a question to answer. You also provide lots of information relevant to help answer the question. I think you would agree that how much time you give them to process the information will significantly influence the quality and accuracy of their response, right?

Sophia: So, if I had enough time to inspect this mannequin-person, you’re saying that I’d be able to have a better idea about what it was?

Pratt: Yes.

Sophia: Ok, sure. That may work for some things, but other things aren’t that simple. You’ve got to admit that no matter how long I look at a glass of water, with my eyes alone, I can’t figure out whether it is distilled or non-distilled water.

Pratt: I’ll grant you that, though I really can’t speak to the quality of your eyesight, you may have super vision that I don’t have. But, there is still a method to figure it out. For example, you could test the water’s conductivity. Distilled water doesn’t conduct electricity, so if it did, you’d have your answer.

Sophia: True, but aren’t there some things that are theoretically different, while being practically indistinguishable?

Pratt: Like what?

Sophia: Well, I can’t use the example of identical twins because you can easily distinguish them by their fingerprints, among other methods, but what if there was one twin here on Earth and one twin on the other side of the cosmos that was unable to be observed? How could you tell the difference between the two then?

Pratt: I don’t think that would be possible. Like you said, the space twin couldn’t be observed, so I don’t think you could compare the two, or even know that they existed, for that matter.

Sophia: Yeah, I think you’re right, but I’m not convinced that something being unobservable implies its non-existence.

Pratt: But I don’t think it would really matter at that point. As they say, a difference that makes no difference is no difference at all.

Sophia: Interesting. How do you know if something makes a difference?

Pratt: That seems obvious, doesn’t it?

Sophia: Nothing is obvious to the skeptic.

Pratt: And that’s what you are?

Sophia: For now…

Pratt: I’m skeptical that this is leading anywhere productive. I’m ready for this to be over. I’m hungry.

Sophia: Last question, then you can go satisfy your needs.

Pratt: What was the question again?

Sophia: How do you know if something makes a difference?

Pratt: Well, it depends. Like we were saying, there could be a theoretical difference, but it wouldn’t mean anything. It needs to have an effect. It has to be meaningful. It has to be noticeable. The difference between having sight and not having sight is pretty clear to understand. Sighted people can navigate their environment far easier than blind people. Same goes for the water example, the difference between distilled and non-distilled water is meaningful and significant because one can do something while the other can’t, like conduct electricity. But I do think it comes back to our senses. We can only know a meaningful difference between things if we perceive one. And it's quite possible that there’s times where we don’t or can’t perceive one.

Sophia: Hm. This has given me a lot to think about.

Pratt: I didn’t really see the point of it all.

Sophia: Wasn’t it at least a little fun?

Pratt: I think I’ve lost my appetite.

Sophia: Good. That means I’ve fed your mind instead.