Atheism, Theism, And the Burden of Proof

I'm going to say something that should be uncontroversial among people who take pride in being rational: one's beliefs must conform with reasons for belief. Quite simply, this means that rationality itself places a burden of proof on everyone to have reasons for their beliefs. But a strange (and frankly, embarrassing) thing happens to many atheists when they enter into a dispute about the existence of God. Suddenly, atheists who would normally agree with what I wrote above, claim that the burden of proof lies squarely and only with theists. Apparently, according to these atheists, as soon as their belief is in question, the burden is entirely on the other side.

How do these folks support the claim that the theist has the sole burden? Their argument goes something like this:

Premise 1: The burden of proof is always on the claimant
Premise 2: Theists are making the claim that God does or probably does exist
Premise 3: Atheists merely lack belief in God's existence and, as such, are making no claim about it.
Conclusion 1: following from (1) & (2), theists have the burden of proof regarding the existence of God.
Conclusion 2: following from (1) & (3), atheists have no such burden.

This would be a valid and sound argument, and a very dandy one for atheists, except for one problem: the claim that atheists just lack belief in the existence of God is often misleading. It fails to accurately describe what most atheists usually think about the probability of God's existence, namely, that it's unlikely. Here's the rub: these atheists think that God probably doesn't exist, and that's a claim about the existence of God. It therefore follows from Premise 1 that they do indeed, have a burden of proof.

So who has no burden?
The only person with no burden regarding a claim is the person who hasn't had enough of a chance to think about the truth or falsehood of the claim and formulate a belief either way. If you haven't had a chance to really think about whether taking in Syrian refugees right now is a good idea, you could say that you "don't believe" that taking them in is a good idea, just as you could say that you "don't believe" that not taking them in is a good idea. You really don't know what to think. When in the psychological state of not knowing what to think about a claim, you really have no burden because you really are making no claim. Please notice that this position poses no challenge to a claim.

The atheists I'm addressing in this post often make the preposterous announcement that they lack belief in God the way a baby or a dog does. While it's true that babies and dogs haven't thought about the probability of God's existence, and therefore make no claim and assume no burden, I can hardly see why atheists would want to bring agents that lack the cognitive abilities to even weigh in on the matter into the fold. I encourage folks who talk like this to think carefully about claiming that they are like opinion-less infants.

There are only 2 ways to challenge a belief
As an atheist, in order to say that you don't believe in God and have that mean anything, you really have to have thought about it and decided that ascent to the claim would be intellectually wrong. You can fail to accept a claim by reaching one of two conclusions:

1. It's probably false. Believing that a claim is more likely to be false than true is a very good reason to not believe the claim. Arguing that a claim is false is known as making a de facto objection. The idea is that there is a fact of the matter regarding the claim and that fact is that it's false, or at least more likely to be false than true.

2. It's unjustified, or irrational. This is a different sort of objection that has nothing whatsoever to do with the veracity of the claim. Rather the objection is that, whether it's true or false, it's unjustified or irrational to believe. This is what's known as a de jure objection.

Here's an example. Say that I produce a lunch box and tell you that there is a hockey puck in it. You could rightly ask why I believe that. Did I look in it and see a puck? Did a reliable source tell me that there is a puck in it? Did I X-ray it and find a puck? If I answer in the negative to all of these sorts of queries, you would rightly question why I claimed that a puck is in the box in the first place. The objection here is that while there could be anything in the box including a puck, the reasons for believing that there is a puck in the box fail to justify that belief, ie. it's irrational.

So atheists have to decide what type of objection to theistic belief they have, and then they have a burden to defend that position. If an atheist thinks that the probability of God's existence is roughly 50/50, they can still advance the damning de jure objection that theistic belief is irrational, and I have absolutely no problem with that, even though most people (myself included) would probably call such a person an agnostic, rather than an atheist. But what atheists shouldn't do is believe in and make de facto objections to theism and then, when challenged, shift the burden of proof onto theists by retreating to a de jure objection, or even worse, to the preposterous position of claiming to have no belief whatsoever regarding the question of God's existence, like a newborn baby. To anybody looking upon this debate with fair eyes, these two moves look lame and shifty because they are.

The guys and gals who behave in the way I am spotlighting are very real and very strongly committed to their fallacious position. In it's defence, you'll hear them say things like:

"The burden of proof is always on the one making a positive claim."
Since the claim that God probably doesn't exist is a negative claim, they are relieved of their burden, or so they assert. But a little reflection reveals that this just isn't true. Imagine that I say that you should take an umbrella to work tomorrow because it's probably going to rain (a positive claim) and you say that you shouldn't because it probably isn't (a negative claim). Am I really the only one among us who has to have a reason for my particular belief? Would you automatically be rational despite having no reasons whatsoever for believing that it probably won't rain? That's nonsense. And besides, negative claims can always be rephrased as positive claims and it's absurd to think that merely rephrasing the same idea suddenly imposes a burden to support it. Here, watch:

Me: "It's not going to be a dry day tomorrow (negative claim), so you better bring your umbrella"

You: "Oh yes it is (positive claim). I'll leave my umbrella at home, thank-you."

By just rephrasing the claim, your negative claim is now a positive claim. Are we really supposed to believe that this rephrasing has suddenly switched the burden from me onto you?

So much for Modified Premise 1. You've got a claim (positive or negative)? You've got a burden.

"But You Can't Prove a Negative!"
One can prove a negative by finding a logical inconsistency in it. For example, I can prove that married bachelors don't exist because they can't. The logical problem of evil represents an attempt to prove that God doesn't exist because of the logical inconsistency posed by an omnipotent and morally perfect God in the face of evil and suffering in the world. Whether this logical argument is successful is another matter, but you get the idea.

One can also argue a negative evidentially. When evidence of a certain kind is expected given a particular claim, the absence of that evidence makes the claim less likely to be true. In other words, sometimes, absence of evidence really is evidence of absence.

For instance, if, whenever you bake a cake, the kitchen smells of baking, then it's reasonable to conclude that you probably didn't bake a cake whenever the kitchen lacks the scent of baking. There are several excellent evidential arguments against the existence of God (I explain a particularly powerful one here) and I encourage atheists to use them.

"No, you're wrong, and Russell's Teapot settles it"
In 1952, Bertrand Russell, a Nobel prize winner and influential philosopher of the 20th century, wrote a paper entitled “Is there a God?” wherein he outlined why he doesn’t believe. Included in the paper is this famous quote:

"Many orthodox people speak as though it were the business of skeptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake. If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense. If, however, the existence of such a teapot were affirmed in ancient books, taught as the sacred truth every Sunday, and instilled into the minds of children at school, hesitation to believe in its existence would become a mark of eccentricity and entitle the doubter to the attentions of the psychiatrist in an enlightened age or of the Inquisitor in an earlier time."

Don't you just love that picture? That's the look I envision on his face when he reminds theists in that quote that it is not enough that theistic belief is widespread and that they therefore have a burden of proof. That's not in dispute. What is in dispute is whether the notion that theism is probably false also has a burden, and nowhere does Russell suggest that it does not.

Russell's teapot is meant to prevent theists from employing the fallacy of "shifting the burden of proof" onto atheists, and that is all. Ironically, atheists who think that God probably doesn't exist and then claim that the burden is entirely on theists to argue that he does are as guilty of shifting the burden of proof as the theists that Russell was scolding. A case of the teapot being as black as the kettle, perhaps?

"But ... The Legal Burden of Proof!"
It is true that in criminal cases, the one charging another with breaking the law (ie. the state) has the burden of proof. The defendant has no burden to prove that she is innocent because she is presumed to be (which doesn't mean that she is, of course). At a minimum, all that the defence must do is show that the prosecution's evidence is weak and therefore raise a reasonable doubt about the accused's guilt. Things are this way to prevent the state from abusing its power. Can you imagine if the state could accuse somebody of a crime and punish them unless they could prove themselves innocent? No person would be free of the threat of that kind of tyranny.

It is noteworthy that the verdict in a criminal case is either 'guilty' or 'not guilty'. Courts never reach a verdict of 'innocent' beyond a reasonable doubt and it would be disingenious for the defence to claim that the defendant was innocent if all they argued was that she was not guilty. Why? Because they would not have met their burden for *that* claim. OJ Simpson was found not guilty, but that clearly didn't mean that he was innocent. Similarly, atheists who believe and claim that theism is probably false are disingenuous if all they do is argue that theistic belief is unjustified or that they lack belief the way a baby does. Why? Because they aren't meeting their burden for the claim that theism is probably false, which is what they really believe.

Outside a criminal court, in discussions about the existence of God, or who would make a good President, or whether the minimum wage should be raised, etc. the burden of proof that matters is the "Philosophical Burden of Proof" and it applies equally to both sides of a claim for we don't presume that a claim is true or false. Accordingly, both sides can be guilty of shifting their burden fallaciously when they try to avoid it.

So there is a reason that criminal courts have an asymmetric burden of proof, but they nevertheless do not reach conclusions beyond what is successfully argued for. If atheists want to avoid their burden of arguing that theism is probably false, they too should not reach or hold conclusions beyond what they are prepared to argue for.

"Extraordinary Claims Require Extraordinary Evidence"
This quote from Carl Sagan is true, to be sure,  but it's also a word game that atheists who want to avoid their burden of proof like to use and it's really quite easy for the theist to dismiss. All the theist must do is ask what makes God's existence an 'extraordinary' claim.

The answer can’t simply be that the evidence and arguments in support of God's existence are insufficient. That only permits one to say that belief in God is unjustified, and while the atheists I'm addressing in this post do think that belief in God's existence is unjustified, they also believe much more than that. They also believe that God's existence is unlikely, and that's a claim that they have to be prepared to back up. You see, saying that a claim is extraordinary is just a dramatic way of saying that it's probably false. The low probability of it being true is what makes the claim that it nevertheless is true, extraordinary. Switching in the word "extraordinary" for "unlikely" doesn't magically make the burden of showing God's existence to be unlikely disappear. And so, when the atheist explains why they think that God's existence is "extraordinary", they will then be addressing the burden of that claim.

"I Don't Have a Burden Because I'm Not Trying to Change Anybody's Mind"
There are 2 responses to this. The first is that if you are involved in a discussion about who has the burden of proof, you are necessarily talking about situations where at least two people disagree and are trying to convince the other of their error. The second is that you have a burden to yourself, in order for your beliefs to be rational, to make sure that they are justified.

"I'm Not Making a Claim to Knowledge"
Here's some important news for anybody tempted to use this canard: if your reasoning is evidence-based, you are always dealing with probabilistic beliefs. Whether you know it or not, when you update your beliefs based on new evidence, you're employing Bayesian reasoning, and the result of Bayesian reasoning is always probabilistic. The difference between a hunch, a belief, and knowledge is just a matter of the probability you assign to the truth of the claim. Your evidence-based reasoning doesn't suddenly acquire a burden of proof when the probability you assign to the truth of a claim reaches whatever threshold you have for calling it knowledge. If you have a hunch, you have a burden. If you have a weak belief, you have a burden. If you have a strong belief, you have a burden. If you think that you "know" something, you have a burden. These burdens are not all equally heavy, to be sure, but they are all very real and shouldn't ever be ignored.

"If I Have To Disprove God, then I Have to Disprove Everything"
This is an obvious non-sequitur. It just doesn't follow from the fact that you must have reasons for your beliefs that you're obliged to anticipate every potential claim and disprove it. You just have to have reasons to support what you've come to believe.

"Prove that unicorns that ride rainbows and fart glitter don't exist"
This was an actual response that I received when I merely suggested that atheists who think that theism is probably false carry a burden of proof. This challenge seems to be a combination of "You can't prove a negative" and "If I have to disprove God, then I have to disprove everything" rolled into one. I suspect that the reasoning was that if one isn't capable of meeting this burden, then it's completely unfair to tell any atheists that they have a burden, too. Here was my response:

"Unicorns are large horse-like animals. Humans have pretty much searched all of the possible habitats for large horse-like animals and reliable evidence of the existence of unicorns, including unicorn remains, unaltered photographs, caged unicorns, etc. have never been produced. Since we could very reasonably expect to find such evidence of the existence of unicorns if they actually existed, the fact that we have not is very powerful evidence against the existence of unicorns. Since we have very powerful evidence against the existence of unicorns, we also have very powerful evidence against the existence of unicorns that ride rainbows and fart glitter. The existence of those specific unicorns, with no evidence in the tree of life of any other animals with such capabilities nor any reason why those capabilities would've evolved, is astronomically unlikely. Furthermore, the notion of  a material being riding a rainbow seems incoherent. The extremely low probability of the existence of such unicorns constitutes what I would consider to be proof that they don't exist. As an epistemic fallibilist, I always leave room for the possibility of being wrong, but the matter has been established to my satisfaction: unicorns that ride rainbows and fart glitter don't exist."

There are some folks who claim to be agnostic about God the same way that they are agnostic about unicorns. I hope it's clear that we don't have to be agnostic about unicorns.

A Way Forward
Because the term 'atheist' is vague and fails to identify whether one has de jure or de facto objections to theism of varying strengths, I propose that people just state what they believe regarding the particular God(s) in question, and how strongly they believe it. In his book, The God Delusion, Richard Dawkins rightfully acknowledged that our beliefs are held with varying degrees of confidence and provided a seven-point scale of belief (more on that here). Notice that the only real "default position", which isn't a position at all, but rather, is the psychological state that exists when someone hasn't yet formulated a belief, isn't even on the scale. Once one forms an opinion about the existence of particular God(s), then atheists and theists alike should figure out where on the scale they sit, and then defend that position. An atheist who's only prepared to claim that theism is unjustified should probably identify as a 4 on that scale. Such atheists really don't have a burden to prove that theism is more likely false than true because they're what most people would call agnostic and are therefore making no such claim. If an atheist identifies between 4.1 and 7, then they have a burden to explain why they think that theism is more likely to be false than true, just as a theist who identifies as a 1-3.9 has the opposite burden. There is no special burden of proof that one side has that the other doesn't, and perpetuating this lie creates a toxic situation where both sides try to shift their burden onto the other. I never want to see my fellow atheists trying to shift their burden onto theists by advancing the lie that they're opinion-less infants, or that their only burden is to reject the evidence and arguments in favour of theism. If you think that God's existence is more likely false than true, you obviously have to do all of that plus more. My request is one that no good atheist should ever resist, for all I'm asking is that you defend what you really believe.

If you want to become familiar with arguments, including evidential arguments, against theism, I suggest following Justin Schieber at Real Atheology, and on Twitter and Facebook.

"Atheists Lack Belief in God" is a Deepity

Many atheists are fond of saying that they "lack belief in God". Unfortunately, this is a vague phrase that can be read in two ways. It's widely accepted and has been the source of much confusion because it is what Daniel Dennett has coined, a deepity. I have written about deepities before here and here.

A deepity is a phrase that balances precariously between two interpretations. On one reading, the phrase is true, but trivially so. On the second reading, the phrase would be profound if it were true, but that second interpretation is actually false. Somehow, the truth of the first reading seems to rub off on the second one, making it seem profound and true.

Here's Dennett's explanation:

 
Let's face it, most atheists think that God's existence is more likely false than true. What else could it possibly mean when they quote their wise sage, Carl Sagan, and tell believers that "extraordinary claims require extraordinary evidence"? To say that they lack belief is, in that case, trivially true. It's trivially true because failure of ascent to the claim "theism is more likely true than false" is entailed by (even mildly) holding the opposite belief.

But the phrase "atheists lack belief in God" can be also be interpreted as follows: atheists have no opinion on whether theism is true or false. Now if that's true, then there's a very profound implication that atheist's seem to love: they have no burden of proof.

Oooooh.

Deep.

Unfortunately, for atheists, it's false*.

Deepities are beguiling, but fallacious. Atheists, who normally take great pride in avoiding fallacies of reasoning, would do well to avoid this deepity and do something that should come easily to those who so strongly endorse rationality: they should take on the burden to defend exactly what they believe.

Philosopher Dan Dennett

*Folks for whom the latter interpretation is true include those who haven't thought about it enough, like a baby, but who in their right mind would call such a person an atheist? Isn't the term supposed to pack even a little bit of a punch? People commonly known as agnostics also have no burden to support the notion that God's existence is more likely false than true, but they do have a burden of rejoinder.

On Disagreement: An Index

Ezra Klein has a great video explaining why wine ranking and pricing is complete bullshit. You can watch it here:

https://www.facebook.com/ezraklein/videos/10153775718848410/

Implicit in his case is the significance of agreement if wine expertise is to be considered a real thing.

Here are links to my five-parter on disagreement and it's important epistemic implications:

Part 1
Part 2
Part 3
Part 4
Part 5

Decisions, decisions ...

Almost three years ago, I accidentally discovered that I have severe aortic heart valve regurgitation (leaking). The only treatment for this problem is surgery, the timing of which is somewhat controversial because we lack the highest quality evidence - multiple randomized controlled rials - addressing that question. Nevertheless, there is reasonable evidence suggesting that the time to operate was not then, and I have been grateful for the three pretty normal years that followed. Unfortunately, it appears that that time has come now.

My left ventricle has shown subtle signs of ongoing dilatation on serial cardiac MRI examinations and that volumetric increase was quite clear on my most recent images. Delaying operation has some benefits that seem largely static with the passage of time while the risk of adverse outcomes increases. The recent dilatation in my ventricle suggests that I'm probably at or near the inflection point of the curve relating the risks and benefits of waiting. It's impossible to know for sure, but I've always wanted to err on the side of operating little bit sooner rather than later if an error had to occur. Accordingly, I am going to wait no longer; my surgery is being planned for early in the new year. But no sooner is that question answered to a satisfactory degree that another question arises: what operation should I have?

The Options

Mechanical valve replacement
This option refers to surgically replacing my aortic valve with one made out of pyrolytic carbon discs that tilt open and closed. The advantage of mechanical valves is that they are very durable. There is probably an 80-90% chance that a mechanical valve will last me the rest of my life. The disadvantage of mechanical valves is that they are foreign material, and the body tends to form blood clots on foreign material exposed to the blood stream. If a blood clot formed on the tilting discs, it could prevent the discs from opening or closing properly. The valve could become severely blocked, impairing the flow of blood out of my heart, and causing a life threatening situation. Alternatively, the clot could break free and travel through just the right blood vessels leading to my brain, causing a stroke. To minimize these clot-related risks, an anticoagulant medication called warfarin is indefinitely required. Because warfarin interacts with changes in diet, liver function, and many medications, regular blood testing to determine the adequacy of anticoagulation are indefinitely required. Thankfully, I could perform these tests at home, about once a week, for the rest of my life. Despite good control of my use of warfarin, I'd probably be facing a 25% life time risk of life-threatening bleeding in the worst case scenario, or enough bleeding to require a blood transfusion in the best. So while there's probably a 75% chance of not having a major bleed, mundane human experiences like a bonk on the head, a car accident, or a bleeding ulcer could all pose serious risks to my well-being.

There are a couple of other considerations regarding mechanical valves. Firstly, they make an audible clicking sound when they close. Sometimes it's loud enough to hear in a quiet room when standing next to someone with a mechanical valve. You can check out what the click sounds like here. Some people are bothered by a sound that they can never get away from, while others get used to it and still others find it soothing or comforting. I'm not sure how I would handle the perpetual click, but I do know that if I can hear my watch ticking on my night table, I can't sleep until I put it away. Secondly, ultrasound examinations of the blood vessels of people with mechanical valves often reveal little specks flying around in the blood stream. These are thought to represent very small blood clots or bubbles, and since they are flying around all over the place, some go to the brain. There is some evidence that patients with relatively high numbers of these tiny emboli have deficits on detailed neurocognitive testing (such as memory defecits). It is unpleasant to speculate that a mechanical valve could lead to early onset dementia. Some biological valves (see below) are associated with these micro emboli, too, though they seem more common among people with mechanical valves.

Biological valve replacement
This option refers to surgically replacing my aortic valve with a new one made out of biologic material from a cow or pig heart. The tissue is treated so as to not invoke an immune rejection response. The advantage of biological valves is that they do not require anticoagulants after the first 3-6 months post-op. The major bleeding risk is therefore about half of that observed with mechanical valves. The downside of biological valves is that they wear down over time and that rate of structural deterioration is fastest in younger patients. A biological valve would be expected to last 10-15 years before requiring replacement surgery, so there is a very high chance that I'd have to have a second open heart operation to replace a biological valve in my lifetime, perhaps, even a third. While the risk of bleeding is lower over those years, the risk of the second surgery is probably double the risk of the initial surgery (though we're still talking about relatively low risks), and if a third operation is required, the risk seems to really increase significantly. Plus, each operation also carries a risk of neurocognitive decline just from being on cardiopulmonary bypass for a few hours. Open heart surgery is basically the mother of all operations, taking 8-12 weeks from which to recover. Nobody wants to have to undergo it more than once if they don't have to...

Mechanical and biological valves compared:
Both mechanical and biological prosthetic heart valves carry a similar and, thankfully, very small risk of becoming infected (endocarditis). This is a serious complication, often requiring redo surgery to remove the infected valve and replace it with a new one. At the end of the day, when these valves have been compared in people over 55, the risk over time of stroke is the same, though mechanical valves require anticoagulants for that to be the case. Survival has seemed pretty much the same, too. With a mechanical valve, the risk of bleeding is spread out over time, while with a biological valve, the risk is concentrated at those times when the valve degenerates and re-operation is required. However, there have been no randomized trials comparing mechanical and biological valves in people in their 40's, so the bottom line is that nobody can provide any confident information about how someone like me ought to expect to fare with either. All one can do is make an educated guess based on trials involving older patients and the best guess of some experts is a mechanical valve, while for others, its a biological one. (Hmmm, an interesting and important disagreement.)

Valve Repair: There is a small chance (estimated at 20-30%), that my aortic valve could be surgically repaired. This would mean that the surgeon could, if the tissues are strong and the valve leaflets long enough, artfully put in some carefully places sutures that would re-align the leaflets and make them close well again. Like a biological valve, repair would have the advantage of not requiring anticoagulants, but more importantly, it would not be associated with an increased risk of infection because no foreign material is involved. The coolest thing about a repair is that while prosthetic valves just palliate the problem, a repair could potentially cure it. The downside of a repair is that its longevity would be unknown. It could last my lifetime, but it could also fail within 2 years and require redo surgery that soon. One estimate is a 20% chance of needing a second operation at or before 10 years. The trouble with these estimates is that the cause of my valve leak isn't known; the usual conditions that cause it have been excluded. Maybe I have weak connective tissues and a repair would be destined to fail again just as my original valve did?

What am I going to do?
Well, I've made a choice, but it's not like I feel very confident about it. I remain open to new evidence and other opinions. At this moment in time, I'm planning to have a surgeon who is very experienced with aortic valve repair - and there are not that many in the world - make a judgement call in the OR: if he thinks that there is a good chance for a durable repair, that is my #1 choice. If he feels otherwise, my second choice is a mechanical valve. The On-X aortic valve has recently been shown to be as safe with less aggressive anticoagulation (INR 1.5-2 rather than 2-3) and therefore less bleeding, so I have asked my surgeon to use this valve if it comes to that.

Repair is attractive because of the lower risk of endocarditis, and because it represents a chance to be normal again. I'm willing to risk something for that, but not much. If the surgeon thinks my tissues are not up to the job of providing me with a lasting competent aortic valve, then I would prefer erring on the side of implanting a mechanical prosthesis. Why mechanical? Because while survival of patients with mechanical and biological valves has been similar in trials of older patients, my suspicion is that there will be a survival advantage in younger patients because the risk of bleeding - the major risk of a mechanical valve over biological - is lower in young patients. Plus, I'm choosing a valve that likely requires less intensive anticoagulation than has traditionally been required, and I would monitor my anticoagulation at home. All of these things should help to reduce the risk of bleeding with a mechanical valve during young years when a biological valve would be undergoing relatively rapid structural deterioration. Also, I somehow feel more comfortable taking my chances with anticoagulants, which I can to some extent control, than with watching and waiting for the clock to tick down to a second big operation. (That doesn't seem like a particularly rational consideration, but I'm with David Hume, whom I must quote at every opportunity: "Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them.")

I wish that there was an ongoing randomized controlled trial comparing mechanical and biological valves in 40 year-olds with long term follow up. I would gladly participate in such a trial and let the study make that decision for me. Unfortunately, and for reasons that are really unclear to me, no such study is underway, nor, to my knowledge, even being planned. It would seem to be so easy to do, and it's a question that's important to many thousands of people like me around the world. Too bad.

So that's likely going to be my roll of the dice. I'll probably end up with a mechanical valve and the best case scenario is that it never gets infected (95% chance), that I have no major bleeding while on warfarin (75% chance), that I get used to the click and even come to like it (? chance), and that it lasts me a long life (80-90% chance) without major neurocognitive decline (? chance). Of course, this discovery has forced me to rethink the concept of a long life: my average life expectancy is probably somewhere around 65* while it ought to be well over 70. And while it would be nice to make it to 75, doing so with cognitive dysfunction represents a particularly unattractive scenario to me. Hopefully, safer alternatives to warfarin will become available for use with mechanical valves in my lifetime.

But like I said, I'm open to other perspectives. Please share your thoughts in the comments below. Would you take a chance at valve repair? Would your back-up plan be a biological valve with a high chance of a second operation, or a mechanical valve with the life-long use of warfarin? How would you roll the dice if you were in my shoes?


*Martijn W.A. van Geldorp , W.R. Eric Jamieson , A. Pieter Kappetein , Jian Ye , Guy J. Fradet , Marinus J.C. Eijke... Patient outcome after aortic valve replacement with a mechanical or biological prosthesis: Weighing lifetime anticoagulant- related event risk against reoperation risk. The Journal of Thoracic and Cardiovascular Surgery Volume 137, Issue 4 2009 881 - 886.e5

What Trophy Hunting Is Forcing Me to Ask

A sportsman and his trophy.

In the last few weeks, we've seen global outrage at the trophy hunting dentist from Minneapolis who wounded and then, 40 hours later, finally killed Cecil the Lion. More recently, we've seen similar outrage over trophy hunting by a child in our own Canadian backyard. This past week, the Wildlife Defence League posted a graphic video on its Facebook page of some hunters playing with the horrible death of a majestic grizzly bear in British Columbia. That video went viral before Facebook pulled it, citing copyright issues. But Gary Mason, National Affairs Correspondent for The Globe and Mail, brought the video back in a piece critical of trophy hunting:

"It seems bizarre that we can be so rightly outraged by the trophy hunting we witness in Africa, but allow the same thing to happen in our own country. Grizzlies in B.C. are being killed for no other reason than for pure pleasure and enjoyment; to provide some testosterone-fuelled “sports hunter” the thrill of killing a defenceless animal that is doing nothing more than innocently ambling about in its home environment." - Mason

I think that Mason captures the reason for the widespread public disgust over trophy hunting, and it has nothing to do with whether the animal in particular is endangered, or in a research study, or a beloved part of a community. On a visceral level, seeming to care so little about the lives and suffering of obviously sentient animals with as strong a will to live as any seems psychopathic. On an intellectual level, the pleasure of the hunter is clearly an insufficient justification for taking the life of an innocent animal.

"What about conservation?" say hunters like Texas millionaire, Corey Knowlton. The problem isn't just that the available evidence supporting conservation is weak and mixed: ecotourism, where the only shots fired are camera shutters snapping away, can bring in many more dollars and place much more value on the lives of wild animals. And besides, if hunters really cared about the lives of their beloved animals, they'd just donate their money to the cause without having to kill any of them. As Ricky Gervais has pointed out, then they'd be heroes.

Non-hunters are quick to come up with a different response. While they frequently condemn trophy hunting, hunting to eat and make use of the carcass is widely considered unproblematic. Mason again:

"And most people accept that grizzlies can and will continue to be hunted by First Nations, but only as a form of sustenance. [But] The notion that some bozo can pay a guide to point him in the direction of a poor defenceless animal and be allowed to brutalize it to death is infuriating. And it has to end." -Mason

Fuelled by celebrity and even New York Times Sunday Review endorsements (albeit based upon arguments with false premises), the eat-what-you-kill movement seems to be growing in popularity. Nevertheless, I'm willing to bet the farm that most of the people who've expressed outrage over trophy hunting think that killing pigs, cows, and chickens for our consumption is just fine, even if you pick them out of a freezer at the grocery store.

But is it?

Let's face it: we don't have to eat meat to survive. We don't even have to eat meat to thrive. Here's a website celebrating elite athletes who are vegans. They don't consume dairy products or eggs, let alone any meat.

Whether we kill animals because we enjoy hunting and stuffing them onto our walls or because we enjoy stuffing them into our mouths, the bottom line is that we're killing animals for our enjoyment. An expert hunter who only kills and eats mature animals with a single shot surely causes much less suffering than our food industry does, but that hunter is still killing sentient animals without adequate justification.

And so it seems to me that if we are to express outrage over trophy hunting, we must ask ourselves a question that's been bothering me lately, and that seems certain to bother future generations, too: where's the outrage over killing animals for the mere pleasure of the meal?

On Disagreement, Part 5: Objections and Conclusion

"Honest disagreement is often a sign of progress"
- Mahatma Gandhi

So far, I’ve discussed three cases (which I’ll call clocks, dress, and cardiology) that illustrate what I consider to be a more widely applicable principle (p) indicating that the right thing to do upon discovering that an epistemic peer disagrees with one after full disclosure is to suspend belief. Today, I’d like to begin examining two lines of criticism of – or disagreement with – this proposition. I'll address them in reverse order. The first is that my proposition is self defeating, and I will bring this up at the end of the post. The second, which I'll deal with first, comes in the form of several other cases where epistemic peers disagree but apparently, “nearly everyone supposes that it is perfectly acceptable for one to (nevertheless) hold fast - i.e. to fail to adjust credences to bring them closer to the credences of another”(1). So let's begin by examining one of several such counter examples as described by philosopher, Graham Oppy, which he calls elementary math:

“Two people who have been colleagues for the past decade are drinking coffee at a café while trying to determine how many other people from their department will be attending an upcoming conference. One, reasoning aloud, says: ‘Well, John and Monima are going on Wednesday, and Karen and Jakob are going on Thursday, and, since 2 + 2 = 4, there will be four other people from our department at the conference’. In response, the other says: ‘But 2+2 does not equal 4’. Prior to the disagreement, neither party to the conversation has any reason to suppose that the other is evidentially or cognitively deficient in any way; and, we may suppose, each knows that none of the speech acts involved is insincere. Moreover, we may suppose, the one is feeling perfectly fine: the one has no reason to think that she is depressed, or delusional, or drugged, or drunk, and so forth. In this case, it seems plausible to suppose that the one should conclude that something has just now gone evidentially or cognitively awry with the second, and that the one should not even slightly adjust the credence she gives to the claim that 2 + 2 = 4.”

Well, of course it seems plausible to us, readers whose independent opinions agree with the one that 2 + 2 = 4, that something has gone cognitively awry with the second! Our opinions serve as additional evidence that alters the 0.5 probability that each disagreeing party is correct. Watch how re-wording the alleged counter example illustrates this reason for its failure:

“You and your colleague for the past decade are drinking coffee at a deserted café while trying to determine how many other people from your department will be attending an upcoming conference. You, reasoning aloud, say: ‘Well, John and Monima are going on Wednesday, and Karen and Jakob are going on Thursday, and, since 2 + 2 = 4, there will be four other people from our department at the conference’. In response, your colleague says: ‘But 2+2 does not equal 4’. Prior to the disagreement, neither you nor your colleague has any reason to suppose that the other is evidentially or cognitively deficient in any way; and, we may suppose, you each know that none of the speech acts involved is insincere. Moreover, we may suppose, you are both feeling perfectly fine with no reason to think that you or the other is depressed, or delusional, or drugged, or drunk, and so forth.”

I hope that you agree that it no longer seems plausible to suppose that you should conclude that something has just now gone evidentially or cognitively awry with your colleague, and that you should not even slightly adjust the credence you give to the claim that 2 + 2 = 4. One of you has a problem, but as bizarre and implausible as this scenario seems, if we are to really consider it a relevant counter example to the principle I have proposed , then neither you nor your colleague can have any reason independent of the disagreement itself to think that the other is the one with that problem. Without a reason independent of your disagreement to justify maintaining your belief, no matter how confident each of you is in being correct, it seems clear to me that you must both suspend belief until further evidence (which is, in this example, easy to acquire) sorts it out. Why? Because, as I have discussed earlier, from an epistemic perspective, neither of you has any reason to think that you are more likely to be correct than the other, so the probability at that point in time that either of you is correct – again, from each of your epistemic perspectives - is 0.5. Since assent to a belief that seems no more likely to be true than false is irrational, suspension of belief is required. Oppy provides several other examples of disagreements concerning “cognitively basic judgments” (those immediately grounded in memory or perception or elementary mathematics), but I think that they all fail for similar reasons. Essentially, if you found dress convincing of my proposition (an example of a cognitively basic judgment), then Oppy’s other similar counter examples should seem pretty unconvincing.

Imagine that you wake up and all of your memories and all of your intuitions tell you that 2 + 2 does not equal 4, while every other person on Earth disagrees. You hold your belief as confidently, sincerely, and intuitively as everyone else. Every time you take two oranges and put them in a box with two other oranges, you count the total number of oranges and you never get 4, while everybody else around you always does. This would be very strange, indeed, but no matter how confident you feel that you know better, I hope you can see that you simply cannot insist that you are right; you must suspend your belief or risk suffering from a delusion. On the other hand, everybody else can draw epistemic confidence in the otherwise perfect agreement that 2+2 does equal 4. Agreement really does matter since it serves to identify what sort of criteria we can use to determine what's normal and what isn't. Here's another example: if you think that killing others for your own pleasure is fine and dandy, and you can't see any problem with that, you're not a lone champion of an obscure moral truth, you're a psychopath.

Alright: I've saved the best for last. The final challenge posed to my proposition is that there appear to exist not just my own epistemic peers, but my own epistemic superiors who disagree with (p), including Dr. Oppy and Dr. Alvin Plantinga, among others. (There are, of course, other philosophers who agree with (p) (or something like it), but the fact that there are those who disagree is the very problem.) Lest I have some way of saving (p) from self-referential defeat, even I must suspend my own belief in it.

But I do have a way of saving (p) from this challenge, at least for now. I have argued logically for (p), and the mere disagreement of epistemic peers or superiors is not enough for me to dismiss it. Recall that (p) requires disagreement despite full disclosure. The latter requires that those who disagree explain which of my premises they disagree with and why. If after such a process, I am left with no reason independent of our disagreement to think that (p) is correct, then it seems that I will have to become agnostic regarding (p) because that's precisely what (p) requires that I do. That hasn't yet happened.

One of my interlocutors on this subject rejected the notion that when n epistemic peers disagree after full disclosure, the epistemic probability that any of them are correct is 1/n, for that is precisely what the disagreement calls into question. I am sympathetic to this criticism, and I interpret it as indicating that it is sometimes very difficult to determine if those disagreeing really are epistemic peers. However, there are times when this really isn't difficult at all, such as, when large groups of people disagree about, for example, cognitively basic judgments, as was the case in dress. Cardiology is a good example of a similar case involving a cognitively non-basic judgment. Relevant epistemic differences will tend to even out among large groups, so if you saw the stripes on the dress as white and gold, and you knew that your spouse saw them as blue and black, you might wonder whether there was something wrong with your spouse visuo-neurologically, but when you realize that there are  literally thousands of people agreeing with you, and thousands of others agreeing with your spouse, it's much more clear that there is something about the situation - about the picture itself - and not with either of the two individuals or camps that is preventing rational assent to a belief about the stripe colors. But this is just to say that the more reasons one has to think that the person disagreeing really is an epistemic peer, the more one must reduce the confidence in one's belief. Interestingly enough, it seems that applying Bayesian math to disagreements among perfectly rational cognizers leads to just this conclusion.

So at least for now, and at least on those occasions where one seems compelled to conclude that the disagreement really is among epistemic peers, (p) still stands. If you know where I might encounter objections to the premises leading to (p), please link or provide references in the comments below. Or even better, explain what they are in your own words. I'm keen to hear all about your disagreement . . .

(1) Oppy, G. Disagreement. Int J Philos Relig 2010 68:183-199.

On Disagreement. Part 4

"Who shall decide, when doctors disagree, and soundest casuists doubt, like you & me?"
-Alexander Pope

Before Angioplasty and After

Duncan was 67 years old when he had his first heart attack. Squeezing chest tightness came on Friday evening while watching ‘Wheel of Fortune’ and didn’t go away when the puzzle was solved. His wife called 9-1-1, and though the discomfort eased off a bit when the paramedics gave him a few puffs of nitroglycerine, they insisted on bringing him to the hospital. His EKG showed signs of a heart attack and an emergency angiogram showed that one of his three main heart arteries was abruptly and completely blocked, depriving valuable heart muscle downstream from much needed blood flow. The discomfort in his chest finally went away when the small balloon his cardiologist had positioned at the blockage was deflated, revealing that the clot that had been blocking the artery had broken up, restoring the flow of blood. A second inflation of a balloon was required to place a metal stent in the artery to help keep it open over time.

Duncan was lucky: the clot that formed in his heart artery and blocked it off had only been present for a few hours, so not much heart muscle damage had occurred. Untreated, a large territory of heart muscle would have been damaged, leaving him with impaired pumping function, a large scar, and a significant risk of life threatening heart rhythm problems. But the prompt opening of the blocked vessel had averted all of that. In a heart attack, time is muscle.

But Duncan wasn’t completely out of the woods.

His angiogram also showed that one of the other two main heart arteries had an 80-90% narrowing in it. Unlike the clot that blocked off his artery in a few minutes when the contestant bought a vowel, this narrowing was the result of cholesterol deposits in the artery wall that had been slowly building up over years. Interestingly enough, it hadn’t caused him any obvious problems, though in retrospect, he had had some of that chest discomfort before when playing with his grand children, which he’d attributed to indigestion.

Cardiologist #1 admitted Duncan to the coronary care unit (CCU) and told him that some time the following week, this other narrowing should also be treated with a balloon and stent, and that made good sense to Duncan, so he approved.

On Monday morning, cardiologist #2 took over the care of the CCU patients for that week, and after reviewing Duncan’s chart, informed him that the plan would be to continue treating him with a variety of new (to him) medications that had all been shown in randomized trials to reduce his risk of subsequent heart attacks and death. Only if he had problems with chest pain that these medications couldn’t prevent, would he undergo angioplasty and stenting of the remaining 80-90% narrowing. Cardiologist #2 explained to Duncan that other randomized trials comparing angioplasty to treatment with medication hadn’t shown an improvement in survival or reductions in heart attacks when stable patients with one narrowed artery were examined. Why undergo the small but real risks of having a second angioplasty procedure if no obvious benefit seemed likely? Besides, if the artery continued to cause problems despite medication in the future, it could always be treated with angioplasty then.

Duncan regrettably agreed with the new plan, and as soon as cardiologist #2 left the room, he called his nurse with a few questions.

“Do these doctors know what the hell they’re doing? ... How come the first doc said that I should have an angioplasty and the second doc said that I should just take pills? ... What are these people’s credentials?"

The nurse explained that cardiologist #1 was the director of the hospital’s angioplasty program and was recognized as a researcher and leader in the field both nationally and internationally. Cardiologist #2 was the Chief of the Cardiology Department, and the Director of the CCU. She was a co-author of the National Guidelines for the treatment of heart attack victims. He explained that both had many years experience looking after patients like Duncan, and that it wasn’t uncommon for experienced and thoughtful cardiologists to disagree about the best treatment for a given patient. He advised Duncan to make his decision about whether to undergo angioplasty or medical treatment on the basis of his personal values, not the current state of the evidence. Does he prefer the idea of taking medicine, which is simple to do? Or does he prefer taking fewer medicines without minding too much about the risk of another invasive cardiac procedure?

But Duncan couldn’t accept that advice. He wanted to do what was best, not what he seemed to prefer for other reasons.

Cardiologists #1 & #2 represent the larger cardiology community on the question raised by Duncan’s situation. On the basis of their interpretation of the available evidence and experience, some recommend opening the remaining narrowings during the initial stay after a heart attack, while others, on the basis of their experience and interpretation of the same evidence, recommend treatment with medicine and opening the narrowing only if further problems arise down the road. What should Duncan do? What should Cardiologists #1 & #2 do? What should the Cardiology community do?

Should Cardiologists #1 & #2 just continue offering their advice to every patient like Duncan that they see? Should Duncan just flip a coin? Should he get a third opinion?

Isn't it obvious? It certainly was obvious to Duncan! They don’t know the answer and further evidence is required to sort the problem out. In this case, Duncan was lucky, because the cardiology community had recognized that there was, regarding the question posed by his circumstances, a condition known as clinical equipoise. This means that the community had come to the conclusion that they ought to suspend their belief because they just don't know. In fact, a randomized clinical trial (RCT) was developed and was enrolling patients just like Duncan to either medical treatment or angioplasty of the remaining narrowing and following subjects closely for the next 4 years to determine which strategy better improved survival, reduced heart attacks, and improved quality of life. The experiment aimed to recruit almost 4,000 patients.

Some philosophers disagree with the approach to disagreement that I have been arguing for so far. They conclude that it’s perfectly rational for Cardiologst #1 & #2 to disagree. But if that’s true, then it’s perfectly acceptable for each to continue treating patients as they rationally believe. If, say, Cardiologist #1 is rational to believe that the best treatment for Duncan is angioplasty, then it’s unethical for her to enroll Duncan in the trial and expose him to a 50% chance of not getting the treatment that she rationally believes is best for him, and vice versa for Cardiologist #2. If every member of the cardiology community maintained their belief in this fashion, none of them would be able to ethically enroll patients in the trial, the trial would never be completed, and the question would never be answered. It is only by recognizing and accepting that they don’t know the answer that it becomes ethical for disagreeing doctors to enroll their patients in the trial and make progress. Not only has much progress already been made this way, but time and time again, what “thoughtful and reasonable doctors” thought was the best treatment has been shown to do more harm than good when properly tested.

Doctors should be accurate with their patients, and that often means being humble about the community's state of knowledge and their own. They should recognize the limits of their personal assessments based on experience. They should tell patients when there is significant reasonable disagreement, and how confident they are of their advice and why. They should fairly often be saying things like “probably”, “possibly” “we really don’t know”, “our best guess at the moment is”, etc., and patients shouldn't get upset with their doctors when they honestly just don't know.

Cardiologists #1&2 should both tell Duncan that they really don't know what should be done about his remaining 80-90% artery narrowing. They should be free to tell Duncan that each has a hunch about what course of action would be best, but that that's all that they have: a hunch. And this is how the rest of us should behave when faced with the reasonable disagreement of our epistemic peers. Admitting that there is a problem with our belief- a problem big enough to justify suspending a previously held belief-  is the first step towards making sure that our beliefs and the strengths with which we hold them accurately map onto reality.

Notice that Cardiologists #1 & #2 should suspend their belief whether or not a randomized trial addressing the question exists, for the existence of the trial in no way affects their inadequate justification. They should suspend belief before the trial exists, while it is being planned, and until the results are published and shown to warrant one approach over the other.

Next time, I'll be looking at a few objections to the approach to peer disagreement that I have been advocating. Have you got any? Do you disagree?