Saturday, December 31, 2011

The Limits of Occam's Razor


Occam’s Razor, also called The Law of Parsimony, is a principle that we shouldn’t add more explanations for a thing than absolutely necessary.  However, popular interpretations of this principle usually go something like “The simpler explanation is to be preferred over the complex one”.  While this does sound appealing on the surface, it is actually a distortion of Occam.  Even worse, this interpretation itself is open to rhetorical abuse.  This is particularly true when people are unwilling to do the actual hard work of considering the totality of the facts, deciding which facts are relevant, then deciding what the facts mean.

The truth is that Occam’s Razor applies only to explanations that account for identical sets of facts.  If the simple explanation takes into account eight relevant facts while the complex ones also take into account those same eight facts and only those eight, then Occam’s razor applies.  However, if the complex explanation takes into account even nine relevant facts, including all eight of the previously stated ones, then we should at the very least not dismiss the more complex explanation from the get-go simply because it’s not as simple as the one that takes into account only the aforementioned eight facts.  The complex explanation might still be wrong anyway, for any number of reasons.  Even so, if it is wrong, it is certainly not due to its complexity; for the explanation takes into account one more relevant fact that the simple one does.  

Occam’s Razor is also easy to abuse rhetorically, especially in light of the above.  This is particularly true with regard to highly complex issues that vex practically everyone – religion, politics, economics, psychology, morality / ethics and so forth.  As emotionally charged as these issues are, these spheres are especially fertile ground for demagogic rabble-rousing.  In these situations, while it may appear the speechmaker seems a master at making the complex clear, it is at least as likely he or she is engaging in oversimple explanations – whether because he or she truly believes their own explanation or merely to provoke people into becoming outraged enough to given them support.  In either case, it is best stop and take a healthy skepticism toward any viewpoint that seems to explain a lot of things, especially about “human nature” issues.   If history and personal experience teach anything, human nature and human actions are often not easily reducible to one simple neat explanation.

So while Occam’s Razor, properly used, is often a powerful tool for discerning the truth of a matter, it’s very appeal as a supposedly simple method of discerning truth from lies makes it very vulnerable to abuse.   Therefore, like any other tool, we should learn what it can and cannot do for us before we actually use it.

3 comments:

Stacy said...

It is true that the most simple explanation is not necessarily the correct one. I am sometimes frustrated with people who believe certain economic issues are simple when in reality they are not. The economy is a very complex system, and an action in one area can have a large effect in other areas. People often fail to consider this, and it can lead to unintended consequences.

Todd said...

Very interesting. I've always disliked the "simplest explanation is best" idea, but I didn't know it was a distortion of Occam's Razor; I just thought Occam's Razor was a poorly-reasoned idea, and couldn't see why everyone was so in love with it.

filrabat said...

Thanks for stopping by, Stacy and Todd.

It is true that the most simple explanation is not necessarily the correct one. I am sometimes frustrated with people who believe certain economic issues are simple when in reality they are not. The economy is a very complex system, and an action in one area can have a large effect in other areas. People often fail to consider this, and it can lead to unintended consequences.

Economic’s complexity approaches that of the human body, if not equals it. It’s like a person thinking jogging, swimming, weightlifting, etc. is the way to proper health thinking that doing more of those things will make them better – only to discover joint cartilage wearing out, overdeveloped muscles over-stressing the heart (I can’t vouch for this one, but this is what I heard from probably 4th or 5th hand information). Then you have the eat only this or that (or don’t) diet – which may clear up the immediate problem but OTOH causes serious deficiencies of other vitamins.


It’s the same for any complex belief system – and there is more complexity to even the simplest things than we realize. Discovering such complexities is what allows us to have the very technology, health care, and conveniences we enjoy today (or even that of somewhat earlier ages).

I suppose simple things are appealing is because, as I said above, it prevents you from having to do the actual hard work of thinking thing through, questioning whether X really does mean Y (or not), and simply putting too much faith in our common sense / animal-based gut instincts. The latter part is particularly subjective, as we all have different experiences and subtlely different types of education, training, and parental guidance (just to name three).


Very interesting. I've always disliked the "simplest explanation is best" idea, but I didn't know it was a distortion of Occam's Razor; I just thought Occam's Razor was a poorly-reasoned idea, and couldn't see why everyone was so in love with it.

It’s said all great thinkers are misinterpreted by lesser minds. That’s why it’s important to go to the source and see for yourself what so-and-so meant. Alas, it’s impossible or impractical to do – given there are many other demands on the average person’s time. Seems like no matter how much “schooling” we get, people are always going to misinterpret the “greats”. Seems like the "greater" the "great", the more gross the misinterpretations of his or her words.