Inference With The Vampire

Being a human is great, except that your lifespan is so short. Just as you start figuring things out, you die. Vampires don’t have this problem.

Let’s do a thought experiment: Imagine a cravat-wearing vampire Count who is one thousand years old. Unlike some vampires, who sleep for centuries, our vampire has been awake the entire time. He has been following what the humans have been doing. As an aristocrat, he appears in high society and keeps up-to-date with philosophy, politics, and current events.

The vampire is immensely knowledgeable. He has been participating in intellectual salons to find victims. He keeps a library of old books in his castle, and he reads avidly in between meals. After centuries of experience interacting with his prey, he has impeccable knowledge of human psychology.

The vampire is old, but he updates his beliefs over time. The vampire would believe in heliocentrism, general relativity, and the germ theory of disease. He would abandon belief in phlogiston. He would accept that the humans have made pretty good progress in the hard sciences.

While the vampire would be impressed with human technological progress, it’s likely that modern moral, social, and political progress would leave the vampire chuckling in the halls of his castle.

Of course, the vampire has a very different morality than humans do, so you wouldn’t want to ask a vampire for moral or political advice. But he does understand human psychology and politics very well, after observing humans for hundreds of years. So we could ask what the vampire would think that humans should do according to their own values, if only they were competent enough to do so.

Epistemology with the vampire

Humans don’t have very much life experience until they get old, at which point everyone decides that they are too cranky to pay attention to.

A thousand-year-old vampire has a lot of life experience (if you can call a vampire’s existence “life”). The vampire has at least ten times more than the average human.

Why is experience so valuable? One possibility is that the more experience you have, the time you have to fix mistakes in your knowledge, like when the vampire abandoned his belief in geocentrism and started believing in heliocentrism because the evidence was persuasive.

Another reason that experience is valuable is that it offers you a sensible set of starting beliefs, background assumptions, or hunches.

A big problem in philosophy is figuring out what beliefs to start out with in the first place. In Bayesian inference, you start with some initial beliefs (called “Bayesian priors” or just “priors”), and then you “update” them as you receive new evidence.

Where do prior beliefs come from? Human philosopher Patrick Suppes has some intriguing ideas:

So, as we turn from truth to the estimation of probabilities, especially Bayesian priors, there are a number of observations with which I want to begin. The first is that such priors are based on a variety of experience, not on the sharp outcomes of well-planned experiments. [...] It is our prior knowledge or experience—and I emphasize experience rather than knowledge, because much of this experience is not consciously articulated—that marks the difference between amateur experimenters and experienced ones. Imagine turning an amateur at loose in a modern physics lab­oratory. In almost any aspect of experiment now conducted in physics, from quantum entanglement to superconductivity, prior experience is the key to success. This kind of experience is gained from the kind of apprenticeship that is very similar to what had been going on for thousands of years in any specialized activity to be found in ancient China, ancient Egypt or ancient Mesopotamia. Put another way, this kind of prior experience is necessary in every aspect of ordinary affairs requiring some kind of learned competence, from driving a car to cooking a decent meal.

This quote says that experience trumps knowledge and experiments. Experience is accumulated over thousands of years. Starting beliefs should be based on prior experience. The amateur in a physics lab thought experiment shows that prior experience matters. You will bungle your investigations if you start out clueless, even if you are going through the motions of doing “science.”

Wouldn’t it be nice if we could talk to someone with thousands of years of experience who could set us straight?

With a thousand years of experience, the vampire is starting to look vastly ahead of humans. We will now underscore some of the ways that the puny humans fall short.

Social science with the vampire

The vampire is incredibly knowledgeable about humans. He gets his knowledge about humans from centuries of experience interacting with them and observing them. Modern humans get their knowledge of humans from their limited experience, from the social sciences of psychology and sociology. The vampire’s knowledge of humans is far superior to our social science. He knows us better than we know ourselves.

Who do you think will make more accurate predictions about humans: a 25-year-old sociology/psychology graduate student who has read a ton of studies, or a thousand-year-old vampire? If you agree with me that the vampire would eat the graduate student alive, then we can conclude that sufficient experience with people can overpower social science.

When the Count turns 1000, a study comes out that contradicts his understanding of human nature. This study has a sample of a couple hundred college students, a p-value of 0.05, it was conducted by a professor who proudly claims a political cause, and the results just happen to line up with that cause. Would the vampire throw out his 999 years of experience and believe this study?

No, he would stick with his prior beliefs and laugh at the puny humans. College students are only good for dessert, not for generating knowledge.

Typical social science studies, which nowadays pass for serious evidence, are immensely weak in comparison to knowledge accumulated over human history. There are probably very few studies that are strong enough to contradict a vampire’s beliefs. If modern people disagree with the vampire about human nature, it’s most likely that the vampire knows what he is talking about and the humans are just wrong.

Politics with the vampire

The problem with being a puny human is that you are automatically a presentist. You are trapped in the conventional wisdom of the Now. Unlike a vampire, you have a very limited amount of time to come to your own conclusions. The vampire has centuries to form his own conclusions.

Humans are always in the grip of some sort of moral crusade or political fad. States and religions rise and fall. But the vampire sits in his castle library, immune to the biasing effects of human politics, mass media, mass education, and clickbait.

Humans have to believe in all sorts of nonsense because it's politically popular or even socially obligatory. The vampire can’t be purged from society or fired from his job for having unpopular opinions. Nobody can fire him from being a vampire.

The vampire is actually an independent thinker. You are not.

Even worse, modern humans are Philistines. They believe the conventional wisdom of the present, looking disdainfully back on the past as an age of darkness.

Why should we look into the past for knowledge, instead of taking our priors from the present? Haven’t smart people in universities already assimilated the past and told us what we need to learn from it? If so, then the vampire wouldn’t have any advantage in wisdom over college graduate students, but I think we already feel that this isn’t the case.

There are good reasons to believe that the modern conventional wisdom has not adequately digested the past. For one example, human societies are constantly undergoing memory wipes due to political and religious disputes and generational fashions. The winners write the history books. This trend is getting especially bad in the age of mass education and mass media.

Humans are constantly destroying their own knowledge. Either they burn each others’ libraries in war, or they have revolutions where they burn their own libraries. Regularly, human politicians come up with schemes like The New Soviet Man and the The Cultural Revolution where they sweep away a lot of their culture’s past knowledge to solidify a particular regime in the present.

Some states broke from the past so completely that they reset their calendars. The French Revolutionaries declared a Year I. The Khmer Rouge in Cambodia decided that even allowing one year of history was too much, and they declared a Year Zero.

A calendar reset is a state symbolically telling their citizens to throw away their entire intellectual history and traditions. If states are willing to forcibly memory-wipe their citizens of culture and tradition, then politics is definitely capable of biasing human knowledge in subtler ways.

Human societies that lose connection with the past are like the protagonist of the movie Memento, whose amnesia causes him to forgot what just happened.

The vampire can’t get brainwashed by human political fads, because he is around the entire time. Unlike humans, he can’t have his entire belief system replaced in between generations. It doesn’t matter that humans keep rewriting their history books; he keeps a fully stocked library of old books in his castle. Nobody can pull a fast one on him.

Rudolf Ritter von Alt library

Approximating the vampire

Unfortunately, we can’t ask a vampire what to believe, because vampires don’t exist—and they are evil.

How can we, with our puny human brains and minuscule lifespans, ever hope to compete with a vampire? Luckily, we are not totally lost. Humans actually have their own sources of vampire-grade knowledge.

Although humans can’t live as long as a vampire, they can still pass down knowledge to the next generation through records, books, art, culture, and traditions. This intergenerational knowledge serves as the starting point for the next generation. We stand on the puny shoulders of the puny humans who came before us. Tradition is Bayesian.

The best approximation for the vampire’s perspective would be to look in the books of the most learned humans of the past.

For all their faults, for all their biases and heuristics, humans went centuries without needing to inflict 5-point Likert scales on college students, and it didn’t stop them from building the entire modern world.

Exercises with the vampire

At this point you might be persuaded that humans are not making the most of their historical experience, and that there is probably something useful from the past that you could learn. You might be wondering how you can think more like a wise, thousand-year-old vampire and less like a puny, Philistine human.

Here are some exercises:

  • Imagine digging up a historical figure you admire, getting them up to speed on everything that’s happened since they died, and then seeing what they think about the questions you are mulling over.

  • When someone is slinging study in your direction, consider where it would persuade a thousand-year-old vampire to shift his beliefs. If not, then perhaps it shouldn’t persuade you, either.

  • Read old books, and talk to your parents and older people. They are your lifeline to the past.

  • Take what the wisest humans believed at an earlier point in time, and make those beliefs your priors. Next, mentally replay everything that has been learned since then, updating as you go. See if you get the same answers as the modern consensus, or if you get different answers.

If you base your prior beliefs on the current conventional wisdom and work backwards, then you end up extremely biased towards the present and you throw out a lot of historical knowledge. Being extremely biased towards the present consensus is a bad bet, given all the knowledge that humans have destroyed and given all the times in history where present consensus has been wrong.

If history was a tape, playing it forwards would look very different from playing it backwards.

What happens if you start with past beliefs that were wrong? Well, if the past was wrong, then you should see centuries of damning evidence that overwhelm it as you move forward through time, like with phlogiston and geocentrism. If a past belief is wrong, then you should be able to fix the mistake by playing history forwards, watch the belief get debunked, and then adopt the new consensus.

But what if you choose a past belief that the present consensus says is wrong, but when you look back through history, you can’t find where it was supposedly slain?

Then congratulations, you’ve found something very interesting. Either the present consensus is wrong, or the issue is still an open question. We will look at some examples in the future.

This methodology is the opposite of what you’ve probably been taught: that the bad old days were full of ignorance, that professors running lab experiments are the pinnacle of knowledge, that traditions are outdated, that religious belief systems are irrelevant, and that your parents don’t know anything.

When you take the accumulated experience of human history as your starting point, then you get some pretty interesting results. Next time you encounter a confusing question, you now have the ability to think like a thousand-year-old vampire, and you can see what new ideas you come up with.

Now put on your cravat and crack open a dusty old book.