Doubting Marcus

Rules? Where We Are Going We Don’t Need Rules

How many flips of a coin coming up heads in a row would it take for you to believe the coin is a trick coin? Two? Ten? 1,000? Our prior belief that any given coin is fair is quite strong but it is not invulnerable to evidence. After say, 15 consecutive heads, the probability we would give to the theory the coin is a trick coin would have raised significantly, but after 1,000 consecutive heads we would have virtually no doubt the coin was a trick coin simply because evidence accumulates. Indeed, after seeing 1,000 consecutive heads seeing the 1,001 toss come up tails shouldn’t suddenly convince you that the coin is fair.

This seemingly tedious example highlights our intuitive grasp of the common dictum extraordinary claims require extraordinary evidence, which is not merely a common phrase but normatively correct. This, for example, is why you believe a friend who says they missed the bus but don’t believe the same friend when they say they slayed a dragon. The kind of evidence is the same, testimony of a friend, and in both cases the friend could be mistaken or lying, but the prior probability you assign to someone missing a bus and someone slaying a dragon are vastly different (and rightly so).

Of course I say seemingly tedious example because though we surely apply this rule regularly there are places where this rule is apparently unwelcome.

Bring up this coin tossing example when discussing telepathy or miracles and you may be regaled with tales of how someone’s personal experience with their favorite belief eliminates the need to consider what we think we know about physics or history. Nevermind the fact they are simply assuming they could not have been mistaken, personal experience simply becomes less important in areas where there is a huge data set. It is true everyone has different experiences but as the data set gets larger our prior beliefs should have less and less bearing on our conclusion. The fact that our prior probabilities of any given coin being fair may have been substantially different matters far more after 15 tosses than it does after 1000.

If you think that 1000 is large, even ignoring the theoretical problems, how large do you imagine the set is of humans failing to demonstrate telepathy or walk on water? To call those sets massive would be an understatement. Likewise in order to overturn our conviction these feats aren’t possible we would need a colossal amount of evidence and surely, as in the case of your friend the dragon slayer, personal testimony doesn’t suffice.

You can’t escape Bayesian reasoning simply by claiming your priors are different, unless of course where you are going you don’t need rules.

_____________________

Update 2/6/13: Removed anomalous indication of a footnote that didn’t exist

My Favorite Terrible Arguments of 2012

Over the course of a year you come across many shockingly poor ideas and arguments in practically every known field. However, some of these claims are so awful I think they deserve special recognition for their unintentional comedy so after the jump are my favorites from the many fields I follow in everything from pseudoscience to economics. And the winners are…

Read More

Apocalypse Briefly: This Time is Different

The end is nigh but I won’t mind much so long as hell has free Wi-Fi.

Of course I tell you this because we all know humanity’s run will be over in a few hours given the coming planetary collision with Niburu, an asteroid impact, the instant shift of the magnetic poles of the Earth, a local supernova, the alien invasion, the Earth being scorched due to a solar maximum and the entire planet being sucked into the black hole at the center of the galaxy all at the same time.

Aside from being a bit of overkill, some doubters have pointed out that it is already December 21st in Sydney and Suva and the world has not ended forgetting to note, as skeptics are wont to do, that obviously the Mayans were referring to December 21st local time which would mean Central Standard Time would apply.

However, if I may take a moment to lay off the sarcasm I’d just like to note claiming the end times are upon us is one of the oldest, and silliest, traditions of humanity going back at least to the Romans and was central in Jesus’ teachings. The so called “Mayan apocalypse” predicted for December 21st, 2012 is not even the only prediction from this year. Yet, like the attempt at creating perpetual motion machines, the latest to claim they have found the secrets which prove the end is coming keep insisting this time is different but failing to offer an explanation as to why it is different.

While some people (like these folks) are going to ruin themselves financially, others (like yours truly) find this prediction as little more than an excuse for a party. Nevertheless what this, and every other doomsday prediction, symbolize to me is the ability of humanity to believe almost anything no matter how farcical it appears from the outside. It is important, then, that we take the steps necessary to explain to people how to avoid such Jedi Mind Tricks such that we don’t believe things which are equally as silly as a planet which doesn’t exist is going to kill us because some hippies misread an ancient calendar of a long-dead civilization.

“Real Magic” and Miracles

Over the course of my life I’ve seen many magic tricks explained and even discovered how a few work on my own. Perhaps that’s why I struggle to imagine how stunned I would be if someone explained a show I saw by saying “That last trick wasn’t an illusion, that was ‘real magic.’” Even if you accepted that “real magic” was possible among the plethora of questions would be why, if the magician is capable of performing “real magic,” do they ever rely on mere trickery to accomplish anything? In this respect I think there are interesting parallels between “real magic,” as opposed to mere illusions, and miracles, as opposed to natural occurrences.

Read More

Science, Science, Science and Then a Miracle Happened

The distinguished lab coat of science should be more appealing than the cloak of the divine but selling miracles wrapped in science has always struck me as odd. There are many people who are determined to stress reliable methods were used to determine the facts surrounding a miracle while simultaneously holding that it is rational to believe the alleged miracle which followed those events was a violation of the natural rules which science and history completely depend on.

This has become a rather wide phenomenon, you see this in creationists somewhat in creationists who argue for Noah’s ark being scientifically believable, but perhaps most prominently this duality of thinking is present in the debate about Jesus’ resurrection. There some theologians impress upon us how good the evidence is that there was an empty tomb while still holding it reasonable to believe the resurrection itself was a miracle. Besides unfailingly being based on misunderstandings of history, science and often requiring lies, it seems more than a bit of an oddity to spend the bulk of your time appealing to science only to conclude with “and then a miracle happened.” I think people who do this have failed to see they undercut their own criteria for what makes a belief reasonable.

Read More

Nessie, Gandalf and Supernatural Explanations

As a high school student, long before I’d ever heard of skepticism or considered arguments for or against naturalism, I wrote a paper on the Loch Ness Monster. Suffice it to say in all my work on that paper I didn’t uncover single credible shred of evidence that Nessie existed yet then I had, and today I still have, a good idea of what it would take to convince me that such a creature does exist. And while the same could be said of most, if not all, cryptozoological creatures the same can not be said for many proposed supernatural creatures or entities.

Read More

Pundits Were Told There Would Be No Math

I once heard a speech on statistics entitled Probability is Hard but if you believe some political pundits like David Brooks a more appropriate name would have been Probability is for Wizards. While believing that polls and the economy can be useful indicators of winning an election Brooks apparently doesn’t believe one can ever place a numerical value on the chance of any outcome. As he told PBS earlier this month:

If you tell me you think you can quantify an event that is about to happen that you don’t expect, like the 47 percent comment or a debate performance, I think you think you are a wizard. That’s not possible. The pollsters tell us what’s happening now. When they start projecting, they’re getting into silly land.

The italics are mine, the basic misunderstanding of probability is his.

Read More

Supernaturalism is Fundamentally Mental

For all my talk of defending naturalism, unfortunately I, like many before me, haven’t made much of an effort to explain the difference between supernaturalism and naturalism. What exactly is the difference between the supernatural and the natural? One of the most useful distinctions I’ve come across, primarily due to aligning with how people use the terms in practice, was made by Richard Carrier who claimed it is between entities which are fundamentally mental and those which are reducible in principle.* That is to say the reason something would be supernatural is not because of the particular powers it exhibits, or because it is currently considered paranormal, but because it would not be reducible to nonmental entities.

Take the competing efforts to explain human consciousness as an example. If naturalism is correct, as I believe it is, then our mental properties are the result of the interaction of nonmental particles, namely the interaction between a vast number of neurons. However, if our mind is not dependent on the brain (or any other sub-component parts) then our mind is supernatural as it is irreducibly mental. The mind would simply possesses mental traits as an innate property.

Read More

Intelligent Design in Practice

I have a challenging question for you: What does Intelligent Design predict? Stumped? Perhaps it’s because, despite the protestations by ID proponents, that it is a trick question. There is a gap between what proponents say and how they behave in practice.

There’s no doubt that if you ask a proponent of ID what it predicts they will rattle off a list including specified complexity, irreducible complexity, no useless DNA, the rapid appearance of complexity in the fossil record, etc. However, this seems to me to be a smokescreen because ID proponents often don’t act as though they believe ID makes those specific predictions.

If you venture over to the Discovery Institute to peek at their definition this is apparent:

The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection

This sounds like something that is testable but the devil is in the lack of detail. If I were to tell you that the atomic theory were incorrect you surely would ask me in what specific manner. However, the major contention of ID in practice, as seen in this definition, is that some yet unspecified dimension of biology is incompatible with evolution by natural selection.* This could be said to be the reason why demonstrating a specific claim of ID to be wrong, like the alleged irreducible complexity of the bacterial flagellum, doesn’t in practice cause proponents of ID to abandon the theory as a whole. The details that a specific example of irreducible complexity is wrong doesn’t matter because, to them, there must be some example of irreducible complexity somewhere. If we can find no irreducible complexity, there must be some other trait which proves design.

They are, in essence, looking at a city which grew organically out of the needs of its people, conceding it looks organic but saying that if we look close enough, we know not where yet, we will find that some portion of the city was planned in some way. Making such an argument fails a test of inference when comparing design to competing hypotheses but for those that attempt to criticize the latest specific arguments of ID proponents ID will always be a shifting target.

_____________________

*It’s also worth noting it could be seen as a straw-man to say evolution is undirected. In a very real sense it is “guided” by whatever currently available mutations exist which is what leads to the incompetent design we all know and loathe.