Wednesday, May 13, 2015

On Disagreement. Part 3

So far in this series, I’ve considered two straightforward instances of disagreement and argued that in each instance, the rational thing to do because of the disagreement is suspend belief (see here and here). Today, I’d like to summarize what I think are the circumstances where disagreement requires suspension of belief.

Quite simply, one should suspend belief whenever, as far as one can know (from an epistemic perspective), the probability that the belief is true is roughly equal to the probability that it is false.

Not all disagreement presents such a situation. For example, Dr. Rik Willems is an expert in the treatment of slow heart rhythm disorders with cardiac pacemakers. If a first-year medical student on her first clinical cardiology rotation thinks that a patient should have a pacemaker implanted, and Dr. Willems disagrees, the probability that Dr. Willems is right is considerably greater than the probability that the medical student is. After all, medical students are supposed to get their plans for patients vetted by attending physicians, not the other way around!

Dr. Willems and the medical student are not epistemic peers. That is, they are not in equally good positions to make judgments upon pacemaker therapy. This is not to say that just because Dr. Willems is in a superior position to make such judgments, that his opinion must be right. The rational thing for him and the student to do is explain to each other the reasons for their opinions. Maybe Dr. Willems has contracted viral encephalitis and evidence of his cognitive dysfunction will be disclosed in the conversation. More likely, however, the medical student has missed an important detail of the patient’s situation, or misinterpreted the available evidence addressing pacing in that situation. This conversation comprises a process known as “full disclosure”; it represents the best possible attempt for disagreeing parties to consider and share the reasons for their own belief and the reasons for the opposing belief. In many such instances, the reasons on one side of the disagreement will really be better and the disagreement will be resolved. We can all, medical students included, learn a great deal this way, even though not all disagreements end so educationally and amicably.

The disagreeing clocks left little to no room for consideration of which time reading was more likely to be correct. Electronic quartz clocks these days are all remarkably accurate, so these two machines are “epistemic peers”. Maybe one had suffered a power loss that the other had not. Maybe somebody spilled a Coke into the one on the night table and caused a malfunction. Or maybe steam and humidity from the adjacent shower caused a malfunction in the bathroom clock. Since the clocks can’t speak and arrive at full disclosure, it seems quite clear that the weight that one must put on the reading of each clock is about equal, and so one must suspend belief about what the time actually is.

The disagreement about the dress also leaves little to no room for consideration of which opinion is more likely to be correct. If just two individuals disagreed, they’d have at least a few things to discuss. Is one looking at the monitor from a particular angle, or in a room with a particular reflection that is affecting her perception? Is one color blind? Is one deceiving the other? But since the disagreement occurred on a global scale, all of these possibilities even out among the two disagreeing camps. Upon becoming aware of the scale of the disagreement, one really is left with no good reason to think that one perception is more likely to be correct than the other, and the rational thing to do is suspend belief. Since the weight of one perception is, as far as anyone can tell, equal to the weight of the other, the circumstances are not unlike considering a coin flip, and this is true even when both parties are disagreeing on the very private evidence of perception.

Why can’t the parties agree to disagree? For the simple reason that both parties have, in the genuine opposition of the other, a good reason to believe that their own perception is, as far as either can tell, the wrong one. Had the opposing belief resided in your own mind – a situation people sometimes find themselves in when they are torn between 2 equally strong but opposing beliefs – you’d be perfectly agnostic. The fact that the opposing belief resides in another mind is, as far as either can tell, arbitrary, and therefore not sufficient to render one belief more likely to be true.

So there we have it.  If epistemic peers disagree after full disclosure, and there remains no good reason independent of the disagreement itself to consider one belief more likely to be correct than the other, the rational thing to do is to suspend belief and try to find other information that will settle the question. If further deciding information is unavailable, either in principle or in practice, then the question will have to just remain open, and cognizers will just have to remain agnostic, at least until such new reasons are available. 

If you think about that for a moment, you should realize that if you accept it, you're going to have to suspend belief about a whole lot of things. This approach to disagreement leads to a significant amount of skepticism, though not, at least as far as I can see, the kind of sweeping philosophical skepticism that is intellectually crippling. We can still believe, for example, that a computer screen is in front of us, that Kennedy was assassinated in the sixties, that OJ was probably guilty (even if that belief isn't beyond all reasonable doubt) and that the gene is the unit of inheritance. But what should minimum wage be? What should be done about income inequality, anthropogenic global warming, and ISIS? Is Allah or Jesus God? These kinds of questions would seem to require the humble approach of agnosticism, and further argumentation, experimentation, and evidence. Sometimes, we are forced to act despite being agnostic, but notice that there's nothing wrong with taking a "best guess" when that's all that is available.

In part 4, I’ll apply this reasoning to a case of disagreement in the Cardiology community and explain how it is being addressed. Chime in now with your own disagreement and you just might find me addressing it in part 5, when I will consider some criticisms of approaching disagreement in the logical fashion I have been describing.

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