# Chastek on Determinism

On a number of occasions, James Chastek has referred to the impossibility of a detailed prediction of the future as an argument for libertarian free will. This is a misunderstanding. It is impossible to predict the future in detail for the reasons given in the linked post, and this has nothing to do with libertarian free will or even any kind of free will at all.

The most recent discussions of this issue at Chastek’s blog are found here and here. The latter post:

Hypothesis: A Laplacian demon, i.e. a being who can correctly predict all future actions, contradicts our actual experience of following instructions with some failure rate.

Set up: You are in a room with two buttons, A and B. This is the same set-up Soon’s free-will experiment, but the instructions are different.

Instructions: You are told that you will have to push a button every 30 seconds, and that you will have fifty trials. The clock will start when a sheet of paper comes out of a slit in the wall that says A or B. Your instructions are to push the opposite of whatever letter comes out.

The Apparatus: the first set of fifty trials is with a random letter generator. The second set of trials is with letters generated by a Laplacian demon who knows the wave function of the universe and so knows in advance what button will be pushed and so prints out the letter.

The Results: In the first set of trials, which we can confirm with actual experience, the success rate is close to 100%, but, the world being what it is, there is a 2% mistake rate in the responses. In the second set of trials the success rate is necessarily 0%. In the first set of trials, subject report feelings of boredom, mild indifference, continual daydreaming, etc. The feelings expressed in the second trial might be any or all of the following: some say they suddenly developed a pathological desire to subvert the commands of the experiment, others express feelings of being alienated from their bodies, trying to press one button and having their hand fly in the other direction, others insist that they did follow instructions and consider you completely crazy for suggesting otherwise, even though you can point to video evidence of them failing to follow the rules of the experiment, etc.

The Third Trial: Run the trial a third time, this time giving the randomly generated letter to the subject and giving the Laplacian letter to the experimenter. Observe all the trials where the two generate the same number, and interate the experiment until one has fifty trials. Our actual experience tells us that the subject will have a 98% success rate, but our theoretical Laplacian demon tells us that the success rate should be necessarily 0%. Since asserting that the random-number generator and the demon will never have the same response would make the error-rate necessarily disappear and cannot explain our actual experience of failures, the theoretical postulation of a Laplacian demon contradicts our actual experience. Q.E.D.

The post is phrased as a proof that Laplacian demons cannot exist, but in fact Chastek intends it to establish the existence of libertarian free will, which is a quite separate thesis; no one would be surprised if Laplacian demons cannot exist in the real world, but many people would be surprised if people turn out to have libertarian free will.

I explain in the comments there the problem with this argument:

Here is what happens when you set up the experiment. You approach the Laplacian demon and ask him to write the letter that the person is going to choose for the second set of 50 trials.

The demon will respond, “That is impossible. I know the wave function of the universe, and I know that there is no possible set of As and Bs such that, if that is the set written, it will be the set chosen by the person. Of course, I know what will actually be written, and I know what the person will do. But I also know that those do not and cannot match.”

In other words, you are right that the experiment is impossible, but this is not reason to believe that Laplacian demons are impossible; it is a reason to believe that it is impossible for anything to write what the person is going to do.

E.g. if your argument works, it proves either that God does not exist, or that he does not know the future. Nor can one object that God’s knowledge is eternal rather than of the future, since it is enough if God can write down what is going to happen, as he is thought to have done e.g. in the text, “A virgin will conceive etc.”

If you answer, as you should, that God cannot write what the person will do, but he can know it, the same applies to the Laplacian demon.

As another reality check here, according to St. Thomas a dog is “determinate to one” such that in the same circumstances it will do the same thing. But we can easily train a dog in such a way that no one can possibly write down the levers it will choose, since it will be trained to choose the opposite ones.

And still another: a relatively simple robot, programmed in the same way. We don’t need a Laplacian demon, since we can predict ourselves in every circumstance what it will do. But we cannot write that down, since then we would predict the opposite of what we wrote. And it is absolutely irrelevant that the robot is an “instrument,” since the argument does not have any premise saying that human beings are not instruments.

As for the third set, if I understood it correctly you are indeed cherry picking — you are simply selecting the trials where the human made a mistake, and saying, “why did he consistently make a mistake in these cases?” There is no reason; you simply selected those cases.

Chastek responds to this comment in a fairly detailed way. Rather than responding directly to the comment there, I ask him to comment on several scenarios. The first scenario:

If I drop a ball on a table, and I ask you to predict where it is going to first hit the table, and say, “Please predict where it is going to first hit the table, and let me know your prediction by covering the spot with your hand and keeping it there until the trial is over,” is it clear to you that:

a) it will be impossible for you to predict where it is going to first hit in this way, since if you cover a spot it cannot hit there

and

b) this has nothing whatsoever to do with determinism or indeterminism of anything.

The second scenario:

Let’s make up a deterministic universe. It has no human beings, no rocks, nothing but numbers. The wave function of the universe is this: f(x)=x+1, where x is the initial condition and x+1 is the second condition.

We are personally Laplacian demons compared to this universe. We know what the second condition will be for any original condition.

Now give us the option of setting the original condition, and say:

Predict the second condition, and set that as the initial condition. This should lead to a result like (1,1) or (2,2), which contradicts our experience that the result is always higher than the original condition. So the hypothesis that we know the output given the input must be false.

The answer: No. It is not false that we know the output given the input. We know that these do not and cannot match, not because of anything indeterminate, but because the universe is based on the completely deterministic rule that f(x)=x+1, not f(x)=x.

Is it clear:

a) why a Laplacian demon cannot set the original condition to the resulting condition
b) this has nothing to do with anything being indeterminate
c) there is no absurdity in a Laplacian demon for a universe like this

The reason why I presented these questions instead of responding directly to his comments is that his comments are confused, and an understanding of these situations would clear up that confusion. For unclear reasons, Chastek failed to respond to these questions. Nonetheless, I will respond to his detailed comments in the light of the above explanations. Chastek begins:

Here are my responses:

That is impossible… I know what will actually be written, and I know what the person will do. But I also know that those do not and cannot match

But “what will actually be written” is, together with a snapshot of the rest of the universe, an initial condition and “what the person will do” is an outcome. Saying these “can never match” means the demon is saying “the laws of nature do not suffice to go from some this initial condition to one of its outcomes” which is to deny Laplacian demons altogether.

The demon is not saying that the laws of nature do not suffice to go from an initial condition to an outcome. It is saying that “what will actually be written” is part of the initial conditions, and that it is an initial condition that is a determining factor that prevents itself from matching the outcome. In the case of the dropping ball above, covering the spot with your hand is an initial condition, and it absolutely prevents the outcome being that the ball first hits there. In the case of f(x), x is an initial condition, and it prevents the outcome from being x, since it will always be x+1. In the same way, in Chastek’s experiment, what is written is an initial condition which prevents the outcome from being that thing which was written.

If you answer, as you should, that God cannot write what the person will do, but he can know it, the same applies to the Laplacian demon.

When God announces what will happen he can be speaking about what he intends to do, while a LD cannot. I’m also very impressed by John of St. Thomas’s arguments that the world is not only notionally present to God but even physically present within him, which makes for a dimension of his speaking of the future that could never be said of an LD. This is in keeping with the Biblical idea that God not only looks at the world but responds and interacts with it. The character of prophesy is also very different from the thought experiment we’re trying to do with an LD: LD’s are all about what we can predict in advance, but Biblical prophesies do not seem to be overly concerned with what can be predicted in advance, as should be shown from the long history of failed attempts to turn the NT into a predictive tool.

If God says, “the outcome will be A,” and then consistently causes the person to choose A even when the person has hostile intentions, this will be contrary to our experience in the same way that the Laplacian demon would violate our experience if it always got the outcome right. You can respond, “ok, but that’s fine, because we’re admitting that God is a cause, but the Laplacian demon is not supposed to be affecting the outcome.” The problem with the response is that God is supposed to be the cause all of the time, not merely some of the time; so why should he not also say what is going to happen, since he is causing it anyway?

I agree that prophecy in the real world never tells us much detail about the future in fact, and this is verified in all biblical prophecies and in all historical cases such as the statements about the future made by the Fatima visionaries. I also say that even in principle God could not consistently predict in advance a person’s actions, and show him those predictions, without violating his experience of choice, but I say that this is for the reasons given here.

But the point of my objection was not about how prophecy works in the real world. The point was that Catholic doctrine seems to imply that God could, if he wanted, announce what the daily weather is going to be for the next year. It would not bother me personally if this turns out to be completely impossible; but is Chastek prepared to say the same? The real issues with the Laplacian demon are the same: knowing exactly what is going to happen, and to what degree it can announce what it knows.

we can easily train a dog in such a way that no one can possibly write down the levers it will choose, since it will be trained to choose the opposite ones.

Such an animal would follow instructions with some errors, and so would be a fine test subject for my experiment. This is exactly what my subject does in trial #1. I say the same for your robot example.

(ADDED LATER) I’m thankful for this point and developed for reasons given above on the thread.

This seems to indicate the source of the confusion, relative to my examples of covering the place where the ball hits, and the case of the function f(x) = x+1. There is no error rate in these situations: the ball never hits the spot you cover, and f(x) never equals x.

But this is really quite irrelevant. The reason the Laplacian demon says that the experiment is impossible has nothing to do with the error rate, but with the anti-correlation between what is written and the outcome. Consider: suppose in fact you never make a mistake. There is no error rate. Nonetheless, the demon still cannot say what you are going to do, because you always do the opposite of what it says. Likewise, even if the dog never fails to do what it was trained to do, it is impossible for the Laplacian demon to say what it is going to do, since it always does the opposite. The same is true for the robot. In other words, my examples show the reason why the experiment is impossible, without implying that a Laplacian demon is impossible.

We can easily reconstruct my examples to contain an error rate, and nonetheless prediction will be impossible for the same reasons, without implying that anything is indeterminate. For example:

Suppose that the world is such that every tenth time you try to cover a spot, your hand slips off and stops blocking it. I specify every tenth time to show that determinism has nothing to do with this: the setup is completely determinate. In this situation, you are able to indicate the spot where the ball will hit every tenth time, but no more often than that.

Likewise suppose we have f(x) = x+1, with one exception such that f(5) = 5. If we then ask the Laplacian demon (namely ourselves) to provide five x such that the output equals the input, we will not be able to do it in five cases, but we will be able to do it in one. Since this universe (the functional universe) is utterly deterministic, the fact that we cannot present five such cases does not indicate something indeterminate. It just indicates a determinate fact about how the function universe works.

As for the third set, if I understood it correctly you are indeed cherry picking — you are simply selecting the trials where the human made a mistake,

LD’s can’t be mistaken. If they foresee outcome O from initial conditions C, then no mistake can fail to make O come about. But this isn’t my main point, which is simply to repeat what I said to David: cherry picking requires disregarding evidence that goes against your conclusion, but the times when the random number generator and the LD disagree provide no evidence whether LD’s are consistent with our experience of following instructions with some errors.

I said “if I understood it correctly” because the situation was not clearly laid out. I understood the setup to be this: the Laplacian demon writes out fifty letters, A or B, being the letters it sees that I am going to write. It does not show me this series of letters. Instead, a random process outputs a series of letters, A or B, and each time I try to select the opposite letter.

Given this setup, what the Laplacian demon writes always matches what I select. And most of the time, both are the opposite of what was output by the random process. But occasionally I make a mistake, that is, I fail to select the opposite letter, and choose the same letter that the random process chose. In these cases, since the Laplacian demon still knew what was going to happen, the demon’s letter also matches the random process letter, and my letter.

Now, Chastek says, consider only the cases where the demon’s letter is the same as the random process letter. It will turn out that over those cases, I have a 100% failure rate: that is, in every such case I selected the same letter as the random process. According to him, we should consider this surprising, since we would not normally have a 100% failure rate. This is not cherry picking, he says, because “the times when the random number generator and the LD disagree provide no evidence whether LD’s are consistent with our experience of following instructions with some errors.”

The problem with this should be obvious. Let us consider demon #2: he looks at what the person writes, and then writes down the same thing. Is this demon possible? There will be some cases where demon #2 writes down the opposite of what the random process output: those will be the cases where the person did not make a mistake. But there will be other cases where the person makes a mistake. In those cases, what the person writes, and what demon #2 writes, will match the output of the random process. Consider only those cases. The person has a 100% failure rate in those cases. The cases where the random process and demon #2 disagree provide no evidence whether demon #2 is consistent with our experience, so this is not cherry picking. Now it is contrary to our experience to have a 100% failure rate. So demon #2 is impossible.

This result is of course absurd – demon#2 is obviously entirely possible, since otherwise making copies of things would be impossible. This is sufficient to establish that Chastek’s response is mistaken. He is indeed cherry picking: he simply selected the cases where the human made a mistake, and noted that there was a 100% failure rate in those cases.

In other words, we do not need a formal answer to Chastek’s objection to see that there is something very wrong with it; but the formal answer is that the cases where the demon disagrees with the random process do indeed provide some evidence. They question is whether the existence of the demon is consistent with “our experience of following instructions with some errors.” But we cannot have this experience without sometimes following the instructions correctly; being right is part of this experience, just like being wrong. And the cases where the demon disagrees with the random process are cases where we follow the instructions correctly, and such cases provide evidence that the demon is possible.

Just a note, one point I am thankful to EU for is the idea that a trained dog might be a good test subject too. If this is right, then the recursive loop might not be from intelligence as such but the intrinsic indeterminism of nature, which we find in one way through (what Aristotle called) matter being present in the initial conditions and the working of the laws and in another through intelligence. But space is opened for one with the allowing of the other, since on either account nature has to allow for teleology.

I was pointing to St. Thomas in my response with the hope that St. Thomas’s position would at least be seen as reasonable; and there is no question that St. Thomas believes that there is no indeterminism whatsoever in the behavior of a dog. If a dog is in the same situation, he believes, it will do exactly the same thing. In any case, Chastek does not address this, so I will not try at this time to establish the fact of St. Thomas’s position.

The main point is that, as we have already shown, the reason it is impossible to predict what the dog will do has nothing to do with indeterminism, since such prediction is impossible even if the dog is infallible, and remains impossible even if the dog has a deterministic error rate.

The comment, “But space is opened for one with the allowing of the other, since on either account nature has to allow for teleology,” may indicate why Chastek is so insistent in his error: in his opinion, if nature is deterministic, teleology is impossible. This is a mistake much like Robin Hanson’s mistake explained in the previous post. But again I will leave this for later consideration.

I will address one last comment:

I agree the physical determinist’s equation can’t be satisfied for all values, and that what makes it possible is the presence of a sort of recursion. But in the context of the experiment this means that the letter on a sheet of paper together with a snapshot of the rest of the universe can never be an initial condition, but I see no reason why this would be the case. Even if I granted their claim that there was some recursive contradiction, it does not arise merely because the letter is given in advance, since the LD could print out the letter in advance just fine if the initial conditions were, say, a test particle flying though empty space toward button A with enough force to push it.

It is true that the contradiction does not arise just because the Laplacian demon writes down the letter. There is no contradiction even in the human case, if the demon does not show it to the human. Nor does anything contrary to our experience happen in such a case. The case which is contrary to our experience is when the demon shows the letter to the person; and this is indeed impossible on account of a recursive contradiction, not because the demon is impossible.

Consider the case of the test particle flying towards button A: it is not a problem for the demon to write down the outcome precisely because what is written has no particular influence, in this case, on the outcome.

But if “writing the letter” means covering the button, as in our example of covering the spot where the ball will hit, then the demon will not be able to write the outcome in advance. And obviously this will not mean there is any indeterminism.

The contradiction comes about because covering the button prevents the button from being pushed. And the contradiction comes about in the human case in exactly the same way: writing a letter causes, via the human’s intention to follow the instructions, the opposite outcome. Again indeterminism has nothing to do with this: the same thing will happen if the human is infallible, or if the human has an error rate which has deterministic causes.

“This means that the letter on a sheet of paper together with a snapshot of the rest of the universe can never be an initial condition.” No, it means that in some of the cases, namely those where the human will be successful in following instructions, the letter with the rest of the universe cannot be an initial condition where the outcome is the same as what is written. While there should be no need to repeat the reasons for this at this point, the reason is that “what is written” is a cause of the opposite outcome, and whether that causality is deterministic or indeterministic has nothing to do with the impossibility. The letter can indeed be an initial condition: but it is an initial condition where the outcome is the opposite of the letter, and the demon knows all this.

# Age of Em

This is Robin Hanson’s first book. Hanson gradually introduces his topic:

You, dear reader, are special. Most humans were born before 1700. And of those born after, you are probably richer and better educated than most. Thus you and most everyone you know are special, elite members of the industrial era.

Like most of your kind, you probably feel superior to your ancestors. Oh, you don’t blame them for learning what they were taught. But you’d shudder to hear of many of your distant farmer ancestors’ habits and attitudes on sanitation, sex, marriage, gender, religion, slavery, war, bosses, inequality, nature, conformity, and family obligations. And you’d also shudder to hear of many habits and attitudes of your even more ancient forager ancestors. Yes, you admit that lacking your wealth your ancestors couldn’t copy some of your habits. Even so, you tend to think that humanity has learned that your ways are better. That is, you believe in social and moral progress.

The problem is, the future will probably hold new kinds of people. Your descendants’ habits and attitudes are likely to differ from yours by as much as yours differ from your ancestors. If you understood just how different your ancestors were, you’d realize that you should expect your descendants to seem quite strange. Historical fiction misleads you, showing your ancestors as more modern than they were. Science fiction similarly misleads you about your descendants.

As an example of the kind of past difference that Robin is discussing, even in the fairly recent past, consider this account by William Ewald of a trial from the sixteenth century:

In 1522 some rats were placed on trial before the ecclesiastical court in Autun. They were charged with a felony: specifically, the crime of having eaten and wantonly destroyed some barley crops in the jurisdiction. A formal complaint against “some rats of the diocese” was presented to the bishop’s vicar, who thereupon cited the culprits to appear on a day certain, and who appointed a local jurist, Barthelemy Chassenée (whose name is sometimes spelled Chassanée, or Chasseneux, or Chasseneuz), to defend them. Chassenée, then forty-two, was known for his learning, but not yet famous; the trial of the rats of Autun was to establish his reputation, and launch a distinguished career in the law.

When his clients failed to appear in court, Chassenée resorted to procedural arguments. His first tactic was to invoke the notion of fair process, and specifically to challenge the original writ for having failed to give the rats due notice. The defendants, he pointed out, were dispersed over a large tract of countryside, and lived in many villages; a single summons was inadequate to notify them all. Moreover, the summons was addressed only to some of the rats of the diocese; but technically it should have been addressed to them all.

Chassenée was successful in his argument, and the court ordered a second summons to be read from the pulpit of every local parish church; this second summons now correctly addressed all the local rats, without exception.

But on the appointed day the rats again failed to appear. Chassenée now made a second argument. His clients, he reminded the court, were widely dispersed; they needed to make preparations for a great migration, and those preparations would take time. The court once again conceded the reasonableness of the argument, and granted a further delay in the proceedings. When the rats a third time failed to appear, Chassenée was ready with a third argument. The first two arguments had relied on the idea of procedural fairness; the third treated the rats as a class of persons who were entitled to equal treatment under the law. He addressed the court at length, and successfully demonstrated that, if a person is cited to appear at a place to which he cannot come in safety, he may lawfully refuse to obey the writ. And a journey to court would entail serious perils for his clients. They were notoriously unpopular in the region; and furthermore they were rightly afraid of their natural enemies, the cats. Moreover (he pointed out to the court) the cats could hardly be regarded as neutral in this dispute; for they belonged to the plaintiffs. He accordingly demanded that the plaintiffs be enjoined by the court, under the threat of severe penalties, to restrain their cats, and prevent them from frightening his clients. The court again found this argument compelling; but now the plaintiffs seem to have come to the end of their patience. They demurred to the motion; the court, unable to settle on the correct period within which the rats must appear, adjourned on the question sine die, and judgment for the rats was granted by default.

Most of us would assume at once that this is all nothing but an elaborate joke; but Ewald strongly argues that it was all quite serious. This would actually be worthy of its own post, but I will leave it aside for now. In any case it illustrates the existence of extremely different attitudes even a few centuries ago.

In any event, Robin continues:

New habits and attitudes result less than you think from moral progress, and more from people adapting to new situations. So many of your descendants’ strange habits and attitudes are likely to violate your concepts of moral progress; what they do may often seem wrong. Also, you likely won’t be able to easily categorize many future ways as either good or evil; they will instead just seem weird. After all, your world hardly fits the morality tales your distant ancestors told; to them you’d just seem weird. Complex realities frustrate simple summaries, and don’t fit simple morality tales.

Many people of a more conservative temperament, such as myself, might wish to swap out “moral progress” here with “moral regress,” but the point stands in any case. This is related to our discussions of the effects of technology and truth on culture, and of the idea of irreversible changes.

Robin finally gets to the point of his book:

This book presents a concrete and plausible yet troubling view of a future full of strange behaviors and attitudes. You may have seen concrete troubling future scenarios before in science fiction. But few of those scenarios are in fact plausible; their details usually make little sense to those with expert understanding. They were designed for entertainment, not realism.

Perhaps you were told that fictional scenarios are the best we can do. If so, I aim to show that you were told wrong. My method is simple. I will start with a particular very disruptive technology often foreseen in futurism and science fiction: brain emulations, in which brains are recorded, copied, and used to make artificial “robot” minds. I will then use standard theories from many physical, human, and social sciences to describe in detail what a world with that future technology would look like.

I may be wrong about some consequences of brain emulations, and I may misapply some science. Even so, the view I offer will still show just how troublingly strange the future can be.

I greatly enjoyed Robin’s book, but unfortunately I have to admit that relatively few people will in general. It is easy enough to see the reason for this from Robin’s introduction. Who would expect to be interested? Possibly those who enjoy the “futurism and science fiction” concerning brain emulations; but if Robin does what he set out to do, those persons will find themselves strangely uninterested. As he says, science fiction is “designed for entertainment, not realism,” while he is attempting to answer the question, “What would this actually be like?” This intention is very remote from the intention of the science fiction, and consequently it will likely appeal to different people.

Whether or not Robin gets the answer to this question right, he definitely succeeds in making his approach and appeal differ from those of science fiction.

One might illustrate this with almost any random passage from the book. Here are portions of his discussion of the climate of em cities:

As we will discuss in Chapter 18, Cities section, em cities are likely to be big, dense, highly cost-effective concentrations of computer and communication hardware. How might such cities interact with their surroundings?

Today, computer and communication hardware is known for being especially temperamental about its environment. Rooms and buildings designed to house such hardware tend to be climate-controlled to ensure stable and low values of temperature, humidity, vibration, dust, and electromagnetic field intensity. Such equipment housing protects it especially well from fire, flood, and security breaches.

The simple assumption is that, compared with our cities today, em cities will also be more climate-controlled to ensure stable and low values of temperature, humidity, vibrations, dust, and electromagnetic signals. These controls may in fact become city level utilities. Large sections of cities, and perhaps entire cities, may be covered, perhaps even domed, to control humidity, dust, and vibration, with city utilities working to absorb remaining pollutants. Emissions within cities may also be strictly controlled.

However, an em city may contain temperatures, pressures, vibrations, and chemical concentrations that are toxic to ordinary humans. If so, ordinary humans are excluded from most places in em cities for safety reasons. In addition, we will see in Chapter 18, Transport section, that many em city transport facilities are unlikely to be well matched to the needs of ordinary humans.

Cities today are the roughest known kind of terrain, in the sense that cities slow down the wind the most compared with other terrain types. Cities also tend to be hotter than neighboring areas. For example, Las Vegas is 7 ° Fahrenheit hotter in the summer than are surrounding areas. This hotter city effect makes ozone pollution worse and this effect is stronger for bigger cities, in the summer, at night, with fewer clouds, and with slower wind (Arnfield 2003).

This is a mild reason to expect em cities to be hotter than other areas, especially at night and in the summer. However, as em cities are packed full of computing hardware, we shall now see that em cities will  actually be much hotter.

While the book considers a wide variety of topics, e.g. the social relationships among ems, which look quite different from the above passage, the general mode of treatment is the same. As Robin put it, he uses “standard theories” to describe the em world, much as he employs standard theories about cities, about temperature and climate, and about computing hardware in the above passage.

One might object that basically Robin is positing a particular technological change (brain emulations), but then assuming that everything else is the same, and working from there. And there is some validity to this objection. But in the end there is actually no better way to try to predict the future; despite David Hume’s opinion, generally the best way to estimate the future is to say, “Things will be pretty much the same.”

At the end of the book, Robin describes various criticisms. First are those who simply said they weren’t interested: “If we include those who declined to read my draft, the most common complaint is probably ‘who cares?'” And indeed, that is what I would expect, since as Robin remarked himself, people are interested in an entertaining account of the future, not an attempt at a detailed description of what is likely.

Others, he says, “doubt that one can ever estimate the social consequences of technologies decades in advance.” This is basically the objection I mentioned above.

He lists one objection that I am partly in agreement with:

Many doubt that brain emulations will be our next huge technology change, and aren’t interested in analyses of the consequences of any big change except the one they personally consider most likely or interesting. Many of these people expect traditional artificial intelligence, that is, hand-coded software, to achieve broad human level abilities before brain emulations appear. I think that past rates of progress in coding smart software suggest that at previous rates it will take two to four centuries to achieve broad human level abilities via this route. These critics often point to exciting recent developments, such as advances in “deep learning,” that they think make prior trends irrelevant.

I don’t think Robin is necessarily mistaken in regard to his expectations about “traditional artificial intelligence,” although he may be, and I don’t find myself uninterested by default in things that I don’t think the most likely. But I do think that traditional artificial intelligence is more likely than his scenario of brain emulations; more on this below.

There are two other likely objections that Robin does not include in this list, although he does touch on them elsewhere. First, people are likely to say that the creation of ems would be immoral, even if it is possible, and similarly that the kinds of habits and lives that he describes would themselves be immoral. On the one hand, this should not be a criticism at all, since Robin can respond that he is simply describing what he thinks is likely, not saying whether it should happen or not; on the other hand, it is in fact obvious that Robin does not have much disapproval, if any, of his scenario. The book ends in fact by calling attention to this objection:

The analysis in this book suggests that lives in the next great era may be as different from our lives as our lives are from farmers’ lives, or farmers’ lives are from foragers’ lives. Many readers of this book, living industrial era lives and sharing industrial era values, may be disturbed to see a forecast of em era descendants with choices and life styles that appear to reject many of the values that they hold dear. Such readers may be tempted to fight to prevent the em future, perhaps preferring a continuation of the industrial era. Such readers may be correct that rejecting the em future holds them true to their core values.

But I advise such readers to first try hard to see this new era in some detail from the point of view of its typical residents. See what they enjoy and what fills them with pride, and listen to their criticisms of your era and values. This book has been designed in part to assist you in such a soul-searching examination. If after reading this book, you still feel compelled to disown your em descendants, I cannot say you are wrong. My job, first and foremost, has been to help you see your descendants clearly, warts and all.

Our own discussions of the flexibility of human morality are relevant. The creatures Robin is describing are in many ways quite different from humans, and it is in fact very appropriate for their morality to differ from human morality.

A second likely objection is that Robin’s ems are simply impossible, on account of the nature of the human mind. I think that this objection is mistaken, but I will leave the details of this explanation for another time. Robin appears to agree with Sean Carroll about the nature of the mind, as can be seen for example in this post. Robin is mistaken about this, for the reasons suggested in my discussion of Carroll’s position. Part of the problem is that Robin does not seem to understand the alternative. Here is a passage from the linked post on Overcoming Bias:

Now what I’ve said so far is usually accepted as uncontroversial, at least when applied to the usual parts of our world, such as rivers, cars, mountains laptops, or ants. But as soon as one claims that all this applies to human minds, suddenly it gets more controversial. People often state things like this:

“I am sure that I’m not just a collection of physical parts interacting, because I’m aware that I feel. I know that physical parts interacting just aren’t the kinds of things that can feel by themselves. So even though I have a physical body made of parts, and there are close correlations between my feelings and the states of my body parts, there must be something more than that to me (and others like me). So there’s a deep mystery: what is this extra stuff, where does it arise, how does it change, and so on. We humans care mainly about feelings, not physical parts interacting; we want to know what out there feels so we can know what to care about.”

But consider a key question: Does this other feeling stuff interact with the familiar parts of our world strongly and reliably enough to usually be the actual cause of humans making statements of feeling like this?

If yes, this is a remarkably strong interaction, making it quite surprising that physicists have missed it so far. So surprising in fact as to be frankly unbelievable. If this type of interaction were remotely as simple as all the interactions we know, then it should be quite measurable with existing equipment. Any interaction not so measurable would have be vastly more complex and context dependent than any we’ve ever seen or considered. Thus I’d bet heavily and confidently that no one will measure such an interaction.

But if no, if this interaction isn’t strong enough to explain human claims of feeling, then we have a remarkable coincidence to explain. Somehow this extra feeling stuff exists, and humans also have a tendency to say that it exists, but these happen for entirely independent reasons. The fact that feeling stuff exists isn’t causing people to claim it exists, nor vice versa. Instead humans have some sort of weird psychological quirk that causes them to make such statements, and they would make such claims even if feeling stuff didn’t exist. But if we have a good alternate explanation for why people tend to make such statements, what need do we have of the hypothesis that feeling stuff actually exists? Such a coincidence seems too remarkable to be believed.

There is a false dichotomy here, and it is the same one that C.S. Lewis falls into when he says, “Either we can know nothing or thought has reasons only, and no causes.” And in general it is like the error of the pre-Socratics, that if a thing has some principles which seem sufficient, it can have no other principles, failing to see that there are several kinds of cause, and each can be complete in its own way. And perhaps I am getting ahead of myself here, since I said this discussion would be for later, but the objection that Robin’s scenario is impossible is mistaken in exactly the same way, and for the same reason: people believe that if a “materialistic” explanation could be given of human behavior in the way that Robin describes, then people do not truly reason, make choices, and so on. But this is simply to adopt the other side of the false dichotomy, much like C.S. Lewis rejects the possibility of causes for our beliefs.

One final point. I mentioned above that I see Robin’s scenario as less plausible than traditional artificial intelligence. I agree with Tyler Cowen in this post. This present post is already long enough, so again I will leave a detailed explanation for another time, but I will remark that Robin and I have a bet on the question.

# Nothing New Under the Sun

Vanity of vanities, says the Teacher,
vanity of vanities! All is vanity.
What do people gain from all the toil
at which they toil under the sun?
A generation goes, and a generation comes,
but the earth remains forever.
The sun rises and the sun goes down,
and hurries to the place where it rises.
The wind blows to the south,
and goes around to the north;
round and round goes the wind,
and on its circuits the wind returns.
All streams run to the sea,
but the sea is not full;
to the place where the streams flow,
there they continue to flow.
All things are wearisome;
more than one can express;
the eye is not satisfied with seeing,
or the ear filled with hearing.
What has been is what will be,
and what has been done is what will be done;
there is nothing new under the sun.
Is there a thing of which it is said,
“See, this is new”?
in the ages before us.
The people of long ago are not remembered,
nor will there be any remembrance
of people yet to come
by those who come after them.

This view is one that maintains neither progress nor regress. While there is change, the change is cyclical, and thus overall things remain the same. This is much like Aristotle’s view of the eternity of the world, although Qoheleth presumably accepts the account of Genesis 1.

Since change implies becoming better or becoming worse, and not all changes are normally undone, it is very hard in practice to maintain such a view. Thus we saw in the post linked above that Aristotle in practice believed not only in the progress of the sciences, but that they had basically reached their perfection.

As a similar example, consider this post by P. Edmund Waldstein:

In his letter to Pliny the Younger on the proper procedure in the persecution of Christians the Emperor Trajan agrees with Pliny that no note is to be taken of libelli containing anonymous denunciations, for, “Nam et pessimi exempli nec nostri saeculi est.” (“They set a bad precedent and are not in the spirit of our age.”) Not of our age! How disappointing that a Roman emperor would sink to the level of that puppet of the contemporary self-congratulatory liberal establishment, the Prime Minister of Canada, who famously justified his cabinet selection with the moronic pseudo-reason “because it’s 2015.” I had thought that this species of idiocy only came into being after Vico, but apparently I was wrong.

If “because it’s 2015” is a “moronic pseudo-reason,” the reason for this would be that time is an accidental feature: 2015 is just one year in history, just like the year 1015, and the year 3015. This suggests a view like that of Qoheleth: times are all alike, not ordered according to better and worse. But like Aristotle, P. Edmund betrays the fact that he does not really accept such a view: “I had thought that this species of idiocy only came into being after Vico, but apparently I was wrong.” If times are all alike, all species of idiocy should exist at all times. The instinct to assume that this is not the case results from the implicit belief that things do indeed change, and indeed become better and worse: it is just that P. Edmund implicitly believes that they become worse, not better, and in this case his implicit belief was not borne out by experience.

Qoheleth in fact knows that many people assume that things are becoming worse, and he rejects this view, precisely because of his position that things are circular.  Thus he says,

Do not say, “Why were the former days better than these?”
For it is not from wisdom that you ask this.

It is not from wisdom to ask this, because the former days were just like these ones. There is nothing new under the sun.

But if this question is not according to wisdom, then just as St. Paul says, “I have been a fool! You forced me to it,” so the present discussion forces us to ask in what way former days were better than these, and why, and in what way worse, and why.

# Patience and Truth

When we consider truth as a good to be sought, the virtue of patience is related to this good in the same way that it is related to other goods. One must seek the truth with an “equal mind,” as St. Augustine says, in order that an unequal mind will not lead one to attempt shortcuts that will not in fact lead towards the truth, but away from it.

As an illustration, we can consider this in relation to our previous discussion of the Jehovah’s Witnesses. We can argue that impatience is involved in their claims, and in several different ways. This will not apply of necessity, of course, to every individual who makes such claims. An individual Witness may simply believe what he has been told by the wisest people he knows, and this may be perfectly reasonable, without any sort of impatience. Nonetheless, I would argue that impatience is involved here in a kind of objective way, and almost certainly with respect to many individuals as well.

In the first place, consider the general claim that apocalyptic events will soon take place. This seems to go back to Nelson Barbour’s argument in his publication Herald of the Morning. Let us look at a few passages, taken from here.

In the book of Daniel, we find a concise history of the world. And those who will compare these prophecies with the facts in history, will find an antidote to infidelity.

That the prophecy was given prior to the Christian era, no one questions. And the evidence is abundant that it was written at about the close of the sixth century, B.C.

Now go with me over the world’s history, and compare it with the prophecy as found in Dan. 7, and then as an honest man, say if one doubt remains, as to its Divine origin.

The four great empires of the world were shown to Nebuchadnezzar in the form of a great image, or likeness of a man; but are here represented to Daniel, as four great wild beasts.

That Babylon, Medo-Persia, Grecia, and Rome, are the four great empires of the world, is known by the veriest schoolboy.

Babylon, founded by Nimrod, the grandson of Noah, was conquered by Cyrus, about 538 B.C. And the kingdom passed into the hands of Darius the Mede, who was father-in-law to Cyrus. And here, “the lion,” Babylon, gave place to “the bear,” Medo-Persia.

The second empire continued a little more than two hundred years, and was then conquered by Alexander the Great; who was the “first king” of the third universal empire; represented in the symbol, by the leopard.

This beast had “four wings,” and “four heads,” denoting a division of the kingdom into four parts, as we are informed.

At the death of Alexander, his four generals shared the kingdom between them. Cassander reigned in Greece, Lysimachus, in Thrace, Ptolemy in Egypt, and Seleucus, in Syria.

This quadrible empire continued about three hundred years, but was eventually subdued by the Romans, B.C. 30.

With the fourth empire, the prophecy enters into very minute detail. Its destructive character, its final division into ten parts, or “horns,” the coming up of another power, “diverse from all the others,” and which was to “wear out the saints of the Most High,” and continue for twelve hundred and sixty years to hold “times and laws,” and afterwards, undergo gradual consumption “unto the end.”

Rome conquered Grecia, and became a universal empire, at about 30 B.C. and so continued, until about the middle of the fifth century, when it was broken into ten fragments. And after that, came up this “little horn,” of which we mean to speak more particularly.

The papacy has its history and character so clearly and minutely recorded here, that we cannot be mistaken in the application.

This “little horn” comes up after the other ten, hence, after the middle of the fifth century. Since “the virgins have been slumbering and sleeping,” some of them have called this “little horn,” the whole eastern empire. But the eastern empire came up more than a hundred and fifty years before Rome was divided into ten parts.

This horn was to “speak great words, and wear out the saints, and think to change times and laws”; all of which was accomplished by the papacy, and not the eastern empire.

After Rome was divided into ten parts, we are to look for a “little horn, diverse from all the others.” The papacy exercised ecclesiastical, as well as civil power, hence, it was different “from all that were before it.” “He shall subdue three kingdoms.” The popes wear a tiara, or three crowned hat; and the map of the Papal States, as they existed a few years since, embraced the territory of three of the original divisions of the Roman empire, viz., Lombardy, the Exarch of Ravenna, and Romania. Sir Isaac Newton, in his dissertation on the Bishop Newton; the Encylopedia of the Royal Society of London for the diffusion of useful knowledge, John Down Dowling, in his History of the Papacy, and all other authorities, outside of certain Adventists, make this same statement in relation to the three horns that were plucked up by this little horn.

The next thing mentioned of the little horn is, “He shall speak great words against the Most High.” I need not stop here to tell you of the great words spoken by the papacy; its history is too well known. “He shall wear out the saints of the Most High.” This also is graven “in blood and flame, and sword and captivity,” on the pages of history. “He shall think to change times and laws, and they shall be given into his hand for a time, times, and the dividing of time.”

Mark the expression, “they, (times and laws) shall be given into his hands.” Who gave them? Let the Bible speak for itself. “These ten kings, … these have one mind, and shall give them power and strength unto the beast.” Rev. 17:12, 13.

Soon after the ten horns came up, they embraced the papal religion, and did “agree and give their kingdom to the beast” until the words of God, viz., “the forty and two months,” or “time, times, and the dividing of time,” was fulfilled.

Ok, you might say, all very well, but this all seems pretty debatable. But even if we assume that it is all correct, how is this supposed to show that apocalyptic events will soon take place? Patience. Barbour’s argument is not a short one.

When the Gothic power was broken in Italy, about A.D. 538, Rome ceased to have a king; and from that date, and for centuries after, the governing power in Rome was of a very mixed and confused character; so much so in fact, that it was difficult to trace its history.

“Times and laws shall be given into his hands, for a time, times, and the dividing of time.” (ver. 26.) The question here arises, why we assume that this period of time is twelve hundred and sixty years? And I shall answer very briefly.

This period occurs here, and in Dan. 12:7, and Rev. 12:14. In Rev. 12 it says, “The woman fled into the wilderness, … and they should feed her there for a thousand two hundred and three score days.” In verse 14 it declares, “She flew into the wilderness, where she is nourished for a time, times, and half a time, from the face of the serpent.” And in Rev. 13:5, we find this power, from which the true church, or “woman,” fled, was to continue forty and two months. In Dan. 11, the margin against verse 13 gives the Hebrew reading, of the meaning of “time,” “Heb. At the end of Times, even Years.” In Hebrew, when two “times,” or “years,” were spoken of, the plural was used, “times”; when more than two, the number was given. Hence, a literal rendering of the above text is, “for a year, two years, and the dividing of a year.” (Dan. 7:26.) This “dividing of a year,” leaves it a little obscure, but in Rev., these three expressions, “time, times, and a half,” “forty and two months,” “a thousand two hundred and three score days,” are used to measure the same period of time, and therefore, these periods must be synonymous. A year is twelve months, two years twenty-four months, and a half year, six months, and together, make the period of forty and two months. A Bible month is thirty days. (See Gen. 7:11.) Where the fountains of the great deep are broken up on the seventeenth day of the second month. And in the seventh month, on the seventeenth day, the ark rested on Mount Ararat. (Gen. 8:4.) “And the waters prevailed upon the earth a hundred and fifty days.” (Gen. 7:24.) From the seventeenth day of the second month, to the seventeenth of the seventh month, is five months; and God said it was “a hundred and fifty days.” Five times thirty is a hundred and fifty. Thus we learn that a time, times, and the dividing of time, or half a time, as given in Dan. 12:7, is 1260 “days.”

A day, when used in prophecy as a symbol, represents a year. (See Ezek. 4:1-6.) But the best of all proof is, the prophecy has been so fulfilled.

In March, A.D. 538, the power of the Goths in Italy was broken; and somewhere about that time, probably near the end of that year, but we cannot determine the month, the provinces of Italy changed their allegiance from the Goths to the Catholic party. “The provinces of Italy had embraced the party of the emperor,” says Gibbon. (See Gib. 1824, page 707.)

Somewhere, then, in the year 538, the provinces, civil power became catholic; and within “one hour,” prophetic time, or fifteen days, (as we shall show on another occasion) from that change of allegiance, the last of the “ten kings” joined the confederacy, and “agreed and gave their power and strength unto the beast.” Here, then, somewhere in the year 538, the papacy began to exercise civil power. And when that church became a civil power, it was numbered among Gentile governments, and became a “horn,” or “beast,” in prophetic language.

Twelve hundred and sixty years from that date the prophecy declares, that “judgment should sit, and they shall take away his dominion, to consume and to destroy it, unto the end.” (Verse 26.) Twelve hundred and sixty years from 538 ended in 1798; and you all know what happened to the papacy. I need not quote history; these facts which I have given, are the outline facts with which all students of history are familiar, and all that is required to establish this application, with absolute certainty, viz. 538, and 1798.

The papacy is organized today — men, women and children, over twelve years of age, all over the world — for the final death struggle. Labor is organized against capital; the Internationals against governments. There are startling events at hand, a time of trouble such as this world has never experienced.

“And the saints of the Most High shall take the kingdom, and possess the kingdom for ever, even for ever and ever.” 1335 prophetic days from where the 1260 began, allowing for certain fractions of a year, which will be made clear in another article, bring us to the end of the world’s history; and complete all the symbols as God has drawn them. This is as certain, and can be made as clear, as is the present application of this prophecy. Is there not, therefore, a plausible argument, at least, that we are on the eve of the Gospel dispensation, and the morning of the next, the glorious age? Then, friends, you who have been waiting long for the coming Bridegroom, take heart, and you who are unprepared for these events, get ready, THE GREAT JUDGMENT DAY IS AT HAND!

I am sure that the reader will be happy to know that I do not intend to include Barbour’s argument for the “1335 prophetic days.” However, his claim here is that the end of the world must come 1335 years after the year 538, or in 1873-1874. His text is written in January 1874, so he is predicting the end of the world within the next twelve months.

One might feel at a loss at how to respond to an argument such as the above: and this is because it is more a series of claims than a series of arguments in the first place. For example, Barbour takes it as obvious that it is the papacy that should be said to “speak great words, and wear out the saints, and think to change times and laws.” No argument is made for this, nor even historical illustrations given of what he is talking about. Perhaps his most important claim is that the papacy became a civil power in 538 and ceased to be one in 1798, and that this reveals a period of 1260 years that corresponds to the prophecy. But it is easy to see that both parts of this claim, both regarding the year 538 and regarding the year 1798, are very questionable interpretations of history, and can represent nothing like the absolute certainty that he says we can have about this part of his interpretation. But even if he was definitely right about his interpretation of the history of the papacy, the period of 1260 years could easily be a complete coincidence, relative to his interpretation of the prophecy. It is evident that many, many things have taken place exactly 1260 years apart; in fact as many as one pleases to find. And of course the fact that the world did not end in 1874 should call into question the whole of his argument, not only the part about the 1335 years.

In any case, Barbour’s claims are rather different from those which the Jehovah’s Witnesses built on them. Barbour ends his article by saying that there is at least “a plausible argument” that the world is about to end, which one finds a bit surprising given that throughout he repeatedly says that his interpretations are beyond reasonable doubt.

Given the objective weakness of Barbour’s argument, a weakness that we can easily discern even without imputing any particular motive, even C.S. Lewis might agree that it would not be absurd to suggest that Barbour is in fact motivated. In fact, the motive is itself not hard to discern. The coming age is “the glorious age.” The sooner, the better, then.

If this is the case, it suggests that the original claim that “apocalyptic events will soon take place,” is an impatient claim, in the most obvious way, namely that the claim is made because of the desire that apocalyptic events take place, and that they take place as soon as possible.

But impatience is involved in another way as well, one that applies more often to other situations besides the particular case of the Jehovah’s Witnesses. A few days ago we discussed the fact that knowledge proceeds from being vague and general to being distinct and more particular, and that the latter knowledge is more perfect.

Now consider the impatience of Peter. In his haste to get home, he omits the good that is needed, namely careful driving, and so fails to get home. In a similar way, someone seeks the truth impatiently who attempts to see the truth in too much detail, too quickly. Patience is needed. As Aristotle says, “For as the eyes of bats are to the blaze of day, so is the reason in our soul to the things which are by nature most evident of all.” When one steps outside on a bright and sunny day, it is often difficult to discern the details of things at first. But wait a while, and the details will become clear. On the other hand, if we step outside and attempt to immediately describe every detail, before things have cleared up, we will almost inevitably be mistaken.

It is easy enough to see this kind of impatience in the history of the Jehovah’s Witnesses. They repeatedly make very detailed claims about the soon-to-occur apocalyptic events, ones that by the very fact that they do not happen, reveal that they are beyond the current ability of the Witnesses to know the truth. Yet because a detailed knowledge would be a more perfect knowledge, impatience for knowledge can lead someone to make such claims before the right time, and thereby lead them away from the truth, just as Peter fails to get home.

# Developing a False Doctrine

As documented here by Paul Grundy, the Jehovah’s Witnesses repeatedly made claims about the end of the world or other apocalyptic events, predicting that they would happen on specific dates. Thus for example they said in 1894, “But bear in mind that the end of 1914 is not the date for the beginning, but for the end of the time of trouble.”And again in 1920:

What, then, should we expect to take place? The chief thing to be restored is the human race to life; and since other Scriptures definitely fix the fact that there will be a resurrection of Abraham, Isaac, Jacob and other faithful ones of old, and that these will have the first favour, we may expect 1925 to witness the return of these faithful men of Israel from the condition of death , being resurrected and fully restored to perfect humanity and made the visible, legal representatives of the new order of things on earth.

Needless to say, these things did not happen. These are only a few examples of false predictions made by the Jehovah’s Witnesses.

To most people, this process seems ridiculous, and to some extent it is. Nonetheless, in a surprising way it is an example of progress in truth. With each failed prophecy, the Witnesses learn something new: first they learn that the world will not end in 1914, then they learn that it will not end or be remarkably restored in 1925, and so on.

The reason this seems ridiculous is that we believe that they should be learning something more. They should be learning that it is false that “apocalyptic events will soon take place and it is within our power to determine in advance their specific timing.” And yes, it would be reasonable for them to learn this. But even if they do not, they are still learning something.

Why do they persist in making the claim that apocalyptic events will soon take place, and that they can determine their timing in advance, even after each particular case is falsified? This is related to our previous post. Their general claim, precisely insofar as it is general, is necessarily more likely, and so “more known”, as it were, than each of the specific predictions. It is as if one were to see something in the distance and to believe, “it is a man,” but then upon getting a bit closer, one says, “wait, it doesn’t look quite like a man, it must be an ape.” The more general belief that it is an animal persists.

The Witnesses may be advancing in truth more slowly than we think that they should, but they are advancing. And ultimately there is no reason to expect this to end with the learning of particulars alone. In fact, towards the end of his article, Grundy says, “Toward the end of the twentieth century, the Watchtower Society refrained from issuing specific dates for Armageddon, but still has not stopped implying dates and time frames.” In other words, they continue to maintain that “apocalyptic events will soon take place,” but they are beginning to conclude that it is untrue that “we can determine their specific timing in advance.” Once again, this is because the claim that apocalyptic events will soon take place is necessarily more likely and “more known” than the combined claim that such events will take place and that one can determine their timing in advance.

# Language as Technology

Genesis tells the story of the Tower of Babel:

Now the whole earth had one language and the same words. And as they migrated from the east, they came upon a plain in the land of Shinar and settled there. And they said to one another, “Come, let us make bricks, and burn them thoroughly.” And they had brick for stone, and bitumen for mortar. Then they said, “Come, let us build ourselves a city, and a tower with its top in the heavens, and let us make a name for ourselves; otherwise we shall be scattered abroad upon the face of the whole earth.” The Lord came down to see the city and the tower, which mortals had built. And the Lord said, “Look, they are one people, and they have all one language; and this is only the beginning of what they will do; nothing that they propose to do will now be impossible for them. Come, let us go down, and confuse their language there, so that they will not understand one another’s speech.” So the Lord scattered them abroad from there over the face of all the earth, and they left off building the city. Therefore it was called Babel, because there the Lord confused the language of all the earth; and from there the Lord scattered them abroad over the face of all the earth.

The account suggests that language is a cause of technology, as when the Lord says, “this is only the beginning of what they will do; nothing that they propose to do will now be impossible for them.”

But is possible to understand language here as a technology itself, one which gives rise to other technologies. It is a technology by which men communicate with each other. In the story, God weakens the technology, making it harder for people to communicate with one another, and therefore making it harder for them to accomplish other goals.

But language is not just a technology that exists for the sake of communication; it is also a technology that exists for the sake of thought. As I noted in the linked post, our ability to think depends to some extent on our possession of language.

All of this suggests that in principle, the idea of technological progress  is something that could apply to language itself, and that such progress could correspondingly be a cause of progress in truth. The account in Genesis suggests some of the ways that this could happen; to the degree that people develop better means of understanding one another, whether we speak of people speaking different languages, or even people already speaking the same language, they will be better able to work together towards the goal of truth, and thus will be better able to attain that goal.

# Predicting the Future

Despite the opinion of David Hume, we find it possible to predict many things about the future. I will have breakfast tomorrow. Some people will celebrate New Year’s Day on January 1st, 2016. The Jehovah’s Witnesses will continue to modify their predictions for the end of the world.

Despite this ability to say a few things about the future, however, if our predictions are sufficiently detailed they are guaranteed to fail. In part this is true simply because our knowledge is not good enough, but there is another reason, one which would guarantee that such predictions would fail even if made by someone with perfect knowledge.

Suppose I have perfect knowledge of the future, and I write down in a book everything that I think you will do for the rest of your life, in nearly every detail, saying at what time of day you will perform various actions such as brushing your teeth, and so on. Then I give you the book. For the first few days, you do everything that is written there, in every detail.

At some point you are pretty sure to wonder whether you can do something different from what the book says. It says that you will eat breakfast at 7:10 AM one morning, so you decide to test violating that, and eat at 7:30 instead. Presumably, nothing will force you to eat breakfast earlier than you planned, and so the prediction will be falsified.

The situation here is very much like the Liar Game in the previous post. The statements have a truth value, and are not objectively paradoxical. But the player cannot get them right, because the truth value of the last statement is anti-correlated with his judgment. In the same way, given human beings with the psychological makeup that they actually have, and the physical abilities that they actually have, a detailed prediction of the future which is known to people will be at least in some respects anti-correlated with reality.

In this sense, the impossibility comes up because the predictions are made known to people. The argument does not prove that there could not be a book somewhere with the whole of the future laid out in detail; but such a book cannot be actually discovered by people without failing to predict the future correctly.