L.A. Paul: Well. So I think that the possibility of becoming a vampire is an intensely interesting one. I like to imagine Dracula coming to you as you’re touring a dungeon, somewhere in Europe, and offering you this irreversible choice. Do you want to join his legions of the undead and get these amazing new sensory powers, and look fabulous and black and be incredible in all sorts of sexy ways? Or, do you want to just like your ordinary life as a human? That’s how he’d put it.

But, there are other ways to think about it. Right? Do you want to sleep in a coffin, never spend another summer’s day on the beach, and drink blood?

Now, I think it’s important to elide moral issues. So, whatever blood you were drinking might be artificial blood, or humanely-farmed animal blood, or something like that. But, it’s a thought experiment designed around one central issue, which is: as you find out about the possibility of becoming a vampire, as you talk to other former humans who are vampires–because, of course, immediately what you do is go out and try to get some evidence and information about what it’s like to be a vampire to make your decision–you find out that, at least according to their testimony, they say you can’t really understand what it’s like to be a vampire until you become one. Mere humans just lack the ability to comprehend the fantastic, supernatural reality that we vampires live.

So, if you’re going to make this choice–let’s say that Dracula’s going to come to you at midnight, you open the window of your Airbnb if you want him to stay and make you one of his–or you keep your window closed and you leave. Your decision is to either embrace him or retract him.

And if that decision is based on whether you want to become a vampire, which turns on what it would be like for you to become a vampire, then you have a problem. Because, if it’s the kind of thing that you can only know and understand once you become a vampire, and if it’s irreversible–this is a one-shot sort of thing–then you lack the kind of information that you need to make an informed decision. Or so I argue. That there’s a problem here. Namely, that you don’t know what it’s like to live your life forward as a vampire. That’s what you’d need to assign value to, in order to decide whether you want to have that life, or whether you want to keep the life that you have.

If you can’t assign that possibility value, at least straightforwardly–value based on what it would be like for you to be a vampire–then your preferences are incomplete, or you haven’t got the information that you need to make the choice in an informed way.

L.A. Paul: Exactly. So, one, there are a number of obvious responses to this initial puzzle that I’d like to talk about. The first thought is, look, ordinarily when you’re thinking about some new thing, like whether you want to build an addition onto your house, you imaginatively model what it would be like to have a house like that or a room like that, and think of yourself enjoying that room–how much you would enjoy it and how much it would cost to build it–and make your decision on that basis. Or maybe you look at a bunch of different plans, and choose between them. That’s just a very natural way to do things. But, in this context, you haven’t got that information, because you can’t know what it’s like to be a vampire, so you can’t model things in this imaginative way.

So, then, what do you do? Maybe you try and get evidence from other vampires, people who’ve become vampires, and find out what it was like for them. If they all seem to like it, maybe that’s just good enough.

But, the problem is–well, there are several problems. But, one problem is that, with this kind of choice, it seems like it changes you in a very deep and fundamental way. It changes, in many ways, who you are. For example, if you become a vampire, you might have very strong opinions about what kind of blood you like, what sort of animals or what sort of artificial construction you prefer. Whereas, I wager, like, right now you probably don’t have those preferences. If you become a vampire, you’ll probably prefer to drink blood over anything else. Like, fine wine just loses its savor. So, there are all kinds of taste preferences that will change. Arguably, you may care less about other people and a lot more about yourself if you’re a vampire. They have a reputation for being narcissists. These kinds of changes are substantial.

In addition, the way that I envision the testimony, is that the vampires say that, ‘This is an incredible amazing experience. You should absolutely do it. It changed my life.’ So, some of your fundamental and core desires and preferences are really just going to be quite different.

Now, if you can’t know what it’s like to be a vampire, yet you know you’re going to change radically, so you can’t project yourself into that possible life, then, there’s a further question about how you’re supposed to evaluate this testimony of these vampires. Because, even though as vampires, they might be incredibly satisfied with the life that they’ve chosen and the way that they are now, how does that compare to what they cared about when they were human? Does it naturally extend–if their preferences changed radically, then whose preferences matter when you make that decision: the preferences of the vampire, or the preferences of the human that made the decision?

L.A. Paul: Right. Okay. So, there are at least three things that I focus on in this situation. Because, absolutely, I mean the normal thing to do in a normal context is to go and get–sometimes people just rely on anecdotal evidence. I think that it’s better to rely on the science, for obvious reasons: It’s vetted. So, let’s pretend that there’s plenty of social science and testimonial evidence from vampires that has been collected up by careful psychologists, economists, sociologists, etc. And, your investigations present you with an assessment of the wellbeing, or life satisfaction, or happiness or whatever it is that vampires experience once they’ve become vampires. How do you evaluate that information as it applies to you?

Now, there are three problems that I think are related here. One, there’s a problem of reference. There’s a reference class problem. Like, you have to know that this evidence applies to you, in the sense that it applies to people like you.

The second problem involves assessing the meaning of an average value result.

And then the third problem which I want to talk about is a little bit conceptually harder; and that involves the problem of this diachronic decision, and the relationship of the testimony, which applies to after-the-fact assessment. And that involves what’s called ‘act-state independence. ‘

So, the first case–

L.A. Paul: Diachronic means across time. So, you make a choice to undergo an experience. You make that choice, let’s say at noon. And then you undergo the experience a few hours later and become a vampire, let’s say, by 5:00 p.m. Let’s say it doesn’t happen instantaneously. Or, even if it does, it takes a couple seconds. So, you’re making a choice at t₁, at noon, for a future self–the one at 5:00 p.m. that’s a vampire. So, it’s diachronic in the sense that it’s across times in a relevant way.

But, the reference class thing is the easiest thing, so let me talk about that first. Ordinarily, when you’re looking at evidence, you need to know that it applies to people like you. In the book, I didn’t even–like, I tried to elide that issue, because I thought there were harder questions and the–

L.A. Paul: Exactly. Exactly. But, like, very loosely, the problems is: Well, how do you know that the population of humans that turn into vampires is a population that’s similar to you in relevant respects? So that you know that you would respond the way that they did, at least in the sense that you would testify relevantly in the same way as they would.

L.A. Paul: Exactly. There’s all kind of black-boxing issues here, all kinds of questions. And, of course, these questions come up with respect to taking ordinary evidence and applying it to this case.

Now, why I think it’s interesting in this case that the reference class problem has some relevance, like special relevance here, is just that: I think with life changing decisions it’s especially important to worry about being a member of the reference class. In low stakes cases you might say, ‘Well, it seems like I’m similar in the relevant ways,’ or maybe things like you mentioned going to college, like standard demographic variables seems like the right ones to rely on: maybe people of my social class, people of my age or whatever tend to have a good effect.

But, something as interesting and distinctive as becoming a vampire–or I talked about other cases, I’m sure we’ll get to them, like cases involving having a child, or a disability, or whatever–it seems like so many other variables matter other than the demographic variables that are usually assessed, that there is a kind of reference class problem here. Because, the properties that seem to matter–how you think you need to be similar to the other individuals who are tested–can be highly variable.

You might not have that information. And, because it’s a life-stakes, high-value, life-changing question, it really matters to you that you get it right. So, just kind of flipping a coin or hoping for the best isn’t good.

L.A. Paul: Exactly. And, sometimes, even the act of making the choice changes you in this irreversible way. Because it’s just such a huge psychological thing to actually make the choice in the first place. And then you can have responsibility to others. For example, the child that you would create, etc.

So, I think the reference class problem, as ordinary as it is, actually takes on special significance in this context.

The same is true of a related thing, which is this question about average values. When you evaluate evidence, and you’re told, ‘Well, people testified to such and such degree of increase in life satisfaction, or decrease, or whatever the question is,’ the values that you get are average values, which means they’re averaged–like, there’s a lot of variation within, like, some kind of span of error. And, again, because we’re talking about high-stakes, life-altering decisions, the fact that you could fall anywhere on a span–like there can be a fairly large or significant error bar with respect to average values–can actually have a huge impact.

So, even if you have the best reasonable evidence that you can have, you still, in a sense, don’t have the right fine-grained evidence about how the value that you would receive, even if you are a member of the reference class, and even if you know that the value that you’re going to get from this change is going to be somewhere along that span. That’s especially important if the error bar extends between positive and negative values.

L.A. Paul: Right. So, the span that matters here is the span between the most negative and the most positive value that you could get that’s consistent with the average value. And of course, what matters is how you would actually respond, and what value you would actually have.

It matters a huge amount. And that’s what we really care about when we’re making a decision. Even independently of: Should we think about maximizing expected value, should–you know, in some larger sense.

Even if we follow the rough guidelines, the fact that the details that we can get given empirical evidence won’t allow us to make a decision even in that framework in the careful way that we want to, is a problem.

Let me say, though, that there’s, again, a special reason why in the kinds of cases I’m interested in, there’s a distinctive problem. The distinctive problem is that in the book I talk about epistemic revelation, and epistemic transformation. And part of what I mean there is that, when you become a vampire–

L.A. Paul: Yeah; I mean, really–yes. And, what I say is that, we can find ourselves in certain situations where we can’t know about something until we actually experience it. And that’s partly just because of the way the brain works. Sometimes description and testimony, just can’t give us what we need. We actually have to have the experience.

And a stock example in philosophy is like the experience of seeing red. You can’t teach someone what it’s like to see red just by describing what it’s like to see red. They have to actually have seen it or at least seen colors very close to it, at best.

L.A. Paul: Okay. So, in–there’s an example by Frank Jackson, where he talks how, about Imagine Mary, he grows up in a black and white environment, has only seen black and white and maybe seen shades of gray, is then faced with the possibility of going out into the rest of the world and seeing color for the first time. Now, Jackson is using this example for a particular argument about consciousness. I’m not making that argument, and so my example’s not quite as constrained as his. But the basic picture is this: That, when Mary leaves–let’s say she goes out there. When Mary leaves her black and white room and sees a red fire engine for the first time, assuming that she has ordinary color vision, she learns something new: What it’s like to see red.

A lot of people, myself included, and the vast majority of philosophers agree with this. And I think non-philosophers also agree with this, to the extent that I’ve talked. So, it really just comes down to, again, the way that the brain works. Sometimes experience teaches us things that we couldn’t know in any other way. If you imagine someone who’s congenitally blind, or congenitally deaf, who then through some kind of surgery gains the capacity to see or the capacity to have ordinary hearing. They are going to learn something new about the world, or they’re going to have new kinds of experiences, basically, from the stimuli that they receive about the world.

And, the thought is that this teaches us that sometimes experience expands us epistemically. It adds or changes what we know, and that we can’t get that from simple description or testimony.

So, going back to the issue that I was talking about with respect to average value, and also to some extent to the reference class problem. But, sometimes when we get a description of the testimony, and we’re told about some possible outcome and how we’re likely to respond–right?–we try to find our own, we try to narrow down I think the information that we’re given by imaginatively reflecting on how we would respond to a particular situation to get an assessment of how we think the claim about the average value is that we’ll receive corresponds to our own best forecasting.

So we forecast for ourselves individually and try to project ourselves forward.

But, in this kind of context, we can’t do it: because we lack the information that we need to be able to do that kind of imaginative projection.

That’s the point. It’s because you have to have the experience that you kind of gain the ability to assess what this experience is like. And so, you can’t actually try to minimize or address the problem of average value in the ordinary way by imagining how you would respond, assuming that there’s an accuracy constraint here, to try to fine-grain the data that you get in some useful way.

So, again, because it’s a transformative experience, involving both epistemic and personal transformation, you find yourself in a high stakes situation, where you lack even the ordinary tools that you might use in ordinary contexts to fix the reference class, and try to fine-grain the average value result for yourself.