Friday, May 30, 2014

The Rarity of "Common Sense"

When I comment on bad laws, and point out flaws by the approach of reductio ad absurdum, the usual response is that we must implement laws using "common sense". Now, this argument is faulty for a number of reasons, most notably that once a principle is allowed in law, it will run to its logical conclusion1, but for the moment let us limit ourselves to "common sense", as it is a topic I have written on several times2.

The problems with common sense are several, but all boil down to a very simple description, that being that if it were truly "common sense" we would not need to point it out or mention it. In other words, being "common" sense, we should all implement it already, without question. If we must debate it, if you must point out "common sense limits" and so on, then it is not "common", it is the position of some subset of humanity. And, if it is not universal, then how do we distinguish "common sense" from the bias, whim, prejudice or just personal values of the speaker? If I say common sense says there should be a minimum wage, how can you tell whether it is "common sense" or my own view?

And the problem is, you can't. There is no such thing as "common sense". If there were, as I said above, we would not need to mention it. Things that are common and automatic, as the assumed definition of "common sense" implies, we do not need to discuss. I don't have to remind you to breathe or eat or drink or use the bathroom. You need to do so, so do I, we do it without discussion or reminders. Common sense, if it truly existed, should be like that. As it is not, then what someone calls "common sense" is inevitably just something he sees as obvious, given his set of values and beliefs, but since neither of those is universal, is nothing like true "common sense" would be.

And, of course, that is assuming the speaker is being honest. Many times, "common sense" is not even what appears obvious to a speaker, but rather an expression of his wishes or biases, something he would like to have happen, but which he is aware is contentious even among those sharing his views and values.

I wrote this because I came across a perfect example of "common sense" diverging. In the US, we assume that people will generally eat something less than a perfect diet. And so, to avoid that problem, our government not only allows vitamins supplementation in food, but encourages it. Even mandates it in the case of folate. And for most people, this would probably be a matter of "common sense", if the foods we eat are likely to leave us vitamin deficient, then we should supplement them. And, if a few citiziens eat a more balanced diet, well almost all vitamins we supplement are water soluble, only a few could cause an overdose, and it is quite unlikely that would happen, so "better safe than sorry"3.

However, Denmark has actually done precisely the opposite, it has enacted laws mandating the opposite. Assuming its citizens receive sufficient vitamin intake from foods, they worry about overdose and ban foods with vitamin supplements4. If a few people might not get sufficient vitamins in their food, they can use supplements, but even the remote risk of overdose is worrisome, so "better safe than sorry".

As you can see, both approach a problem that can be argued either way. Granted, Danes and Americans eat differently, but the truth is, the risks involved are all somewhat small. As our wealth has increased, even "eating junk"5, our nutrition has improved incredibly over our ancestors. Yes, some less common nutrients, such as folic acid, may be somewhat deficient and supplements can have a benefit for some, but without supplements or with, true deficiency, as opposed to low levels with long term negative side effects, would be relatively uncommon. On the other hand, the risk of vitamin overdose from fortified foods is equally remote. Most vitamins which are fortified are water soluble, and those which are not take relatively large amounts to produce any sort of negative effect. (As with deficits, some may argue for long term effects of moderately elevated levels, but there is not a lot of evidence to back this up.)  So, the "common sense" on both sides amounts to assessing one remote risk against another. However, US common sense and Danish completely disagree.

I grant, they are looking at different circumstances, but it is not as broad a difference as many think. US diets have, in general, improved greatly during the 20th and 21st centuries. For all the talk of "over processed"6 food and the like, we have a more diverse and more balanced diet than was common for the same social stratum 100 years ago. It is silly primitivism to imagine that city workers in the 19th century, or even farm hands, ate a better, more healthy diet than we do today7.But, regardless of the quality of the general US diet, there are many in the nation who eat a balanced diet, and have as great a risk of overdose as Danes do. Likewise, there are certainly Danes who eat poorly and would benefit from supplements, so both risks exist in both nations, making the divergence of "common sense" answers more striking.

Of course, the reason for this divergence is obvious. There is no "common sense" answer, as "common sense" is a fiction. Both nations enacted laws based on their own presumptions and biases, which they saw as "common sense", as every one of us tends to assume his beliefs are the standard of truth, the baseline against which other beliefs should be measured8. However, in truth, the decisions were no more "common sense" than all the decisions you made in the preceding week, or those I made. All decisions are the product of a personal values, and no set of personal values is so impeccable as to be deemed "common sense".

And thus, to claim we must use common sense to pass laws, or to limit some bad principle is to say we must cure one ill with another, we must base all future laws on some arbitrary set of values lest we go too far with a bad law9. And that seems a pretty bad way to create government policy.


1. The reason is obvious. As I have written in "Inescapable Logic", "Recipe For Disaster", "The Endless Cycle of Intervention" and "The Cycle of Compassion", the most consistent argument wins, and once a principle is allowed, the one which applies it most broadly is most consistent. So, even if the majority believes a principle should be taken only "so far", someone usually stands to benefit from a little wider application, and, being more consistent, will inevitably win their argument. Of course, someone else likely stands to benefit from an even wider implementation, and so takes it a bit farther still, and so on, and so on. And, in the end, we have Griswold allowing married couples to use condoms being mutated into Roe and arguments for unlimited access to publicly funded abortion. (Or to be less contentious, we have the commerce clause changing from  a power to strike down interstate tariffs to Munn v Illinois which claims commerce exclusively within a state can be regulated because it "effects" interstate commerce.)

2. See "The Lunacy of "Common Sense"", ""Seems About Right", Another Lesson in Common Sense and Its Futility", "A Look at Common Sense", "Res Ipsa Loquitur", "The Shortcomings of Pragmatism", "Pragmatism Revisited", "Pragmatism Revisited, Again", "The Plural of Anecdote is Not Data", "Rules of Grammar and Pragmatism", "The Problem of the Small Picture", "Keyhole Thinking", "Impractical Pragmatists", "In Defense of Zero Tolerance, or, An Examination of Law, Common Sense and Consistency", "No Dividing Line", "The Consequences of Bad Laws" and "Questions of Law and Questions of Fact".

3. I have refuted "better safe than sorry" thinking in my essay ""Better Safe Than Sorry" Usually Leaves Us Even More Sorry, And Much Less Safe".

4. I also read a second theory, that foods with vitamin supplementation were mostly "junk foods" and so the Danes banned them to encourage "healthy eating". but as the articles I found were mostly about banning Marmite, Vegemite and the like, which are hardly traditional junk foods, that seems unlikely, though some may have based their decision on that assumption.

5. Considering the amount of starch eaten by our ancestors, claiming we eat a diet high in "empty calories" and "excessive carbohydrates" is absurd. When your main foodstuff is bread or porridge or grits, sometimes supplemented with some bacon grease, or maybe a bit of salt pork, with vegetables rare and fruits even more so, changing to the modern diet would seem a positive godsend, not to mention a health boon.

6. See "The High Cost of Not Wasting Food" and "In Defense of White Bread". Also "GMO? So What?", "A Misleading "Right to Know"", "Organic Absurdities" and "Irrational Environmentalism".

7. There were many in the 18th and early 19th century who noted the citizens of the US ate to excess, wolfed down huge amounts of mostly starches, and were regular users of patent remedies for gas and constipation. Vegetables were rare in many diets, as were fruits. So, it is a laugh to imagine our diet is somehow inferior to that of our ancestors. And comparing our middle class or lower class diet to a single example from say, Thomas Jefferson's diaries or some other uncommon individual of the upper classes is hardly a valid way to establish a decline in quality of food. See also "Mistaken Perceptions of the Industrial Age"and "Peaceful Matriarchies, Noble Savages and the Industrial Revolution". For my objections to primitivism in general, see "Primitivist Delusions",   "Rousseau's Foolish Legacy", "The Dishonesty of Avatar", "Happiness", "Opinion Masquerading as Fact", "A Western Evil?", "A Great Quote", "Stupid Quote of the Day (January 11, 2012)", "Contradictory Positions", "Deceiving Themselves?", "Stupid Quote of the Day (December 28, 2011)", "A Beast's Life" and "The Hunter-Gatherer Mistake".

8. Often this is a wholly unconscious practice. We are so familiar with our own beliefs and prejudices, we find them so self-evident, that we forget there are those who do not follow them. See "The "Liberal Bubble" Becomes Universal" and ""Nobody I Know Voted For Nixon"".

9. This is less clear than I had hoped. Basically, I am trying to combine the arguments of "The Consequences of Bad Laws" and "The Inherent Disappointment of Authoritarianism", if that makes sense.



For those who would ask "which do you favor?" I would answer "neither". The state should just stay out of the matter, and allow buyers and sellers to decide whether or not to supplement foodstuffs. If the supplements are in enough demand, then they will be sold. And, if they prove dangerous, well buyers will begin to avoid them, maybe even sue if the danger is a result of some actionable deed (such as supplementing to a toxic level in a single serving), and sellers will remove or change the level of fortification.

Allow me a small personal digression. Due to my ailments, I tend to avoid sunlight for the most part, and I am also not a milk drinker. As a result, I have a chronic vitamin D deficiency. Yet, unlike most of those "sick celebrities" who contract a disease and suddenly become advocates (and overnight experts), this does not make my clamor for supplements of D in ever substance known to man. Instead, I simply take it upon myself to take supplements and have my blood checked periodically. Problem solved. And all without massive government intrusion.

And, in the long run, I believe most people will resolve these problems in similar ways. Some will rely on fortified foods to get vitamins, some will eat a varied diet (with or without fortified foods), some will avoid "over processed' foods, some won't, some will take vitamin supplements, some won't, but in the end, all of us will do what we think best in terms of nutrition, and most of us will probably do pretty well. A few won't, but no law is going to save everyone, so to hold the free market to a standard of perfection is pretty absurd. (See "Third Best Economy" and "Government Quackery".)


  1. No such thing as common sense? Thomas Paine must be rolling over in his grave, Andrew.

    First let’s be clear on what the definition of “common sense” is. According to the Merriam-Webster Dictionary, “commons sense” is defined as:

    “sound and prudent judgment based on a simple perception of the situation or facts.”

    Secondly, no one is suggesting that common sense be the main driver of our laws, so it’s puzzling to me that you seem so obsessed with it, if I may say so. Laws are made to protect people’s rights, for safety and for the sake of promoting common values in the community. The only way common sense factors in there is when a law doesn’t conform to its stated purpose. If I want to pass a law against red hats on the basis that they’re an eyesore, for instance, that’s not going to meet the test of common sense since there’s no commonly shared repugnance towards red hats and also because there’s no recognized right not to be offended in that way. To say that we shouldn’t pass laws because we can’t rely on that type of common sense would be like me saying that you should never let your son go outside alone no matter how old he gets because you can’t be sure he’ll use common sense and he might fall into a sewer pipe or ride his bike in traffic, etc. I assume you’ve taught your son a thing or two and I assume he’s a bright kid but of course things happen and kids don’t always make the right decisions. That’s just a risk you’ll have to take unless you want to be ridiculously cautious and keep him indoors all his life. The same logic applies to the passing of laws. Yes, it’s a risk to rely on common sense to prevent bad laws, but the alternative of saying that society can’t pass any laws is absurd, if that’s what the alternative is (and please correct me if you’re suggesting otherwise).

    Finally, you said, “…to claim we must use common sense to pass laws, or to limit some bad principle is to say we must cure one ill with another…”

    I would respond by saying that to say society can’t pass laws because they’ll rely on common sense and might end up with bad laws is to say we must cure one ill with another.

  2. I argue against common sense for precisely the reason I state here. Yes, perhaps in some everyday usage we could say "X is common sense", which means, loosely, "to anyone who has a fair amount of understanding X is self evident". The problem is, that is then extrapolated to politics, where "self evident" is a very tricky proposition, and used to undermine principles.

    For example, whenever I point out that the same rationale that argues for banning drugs could be used to ban guns, the response often is "well, we must use common sense". There, the argument does not work. For, as I have said, common sense in politics is much different from telling you to turn pot handles inward when cooking or to look both ways before crossing the street. Often what seems self evident in politics (eg that people can't shoot each other if they don't have guns, so gun bans end violence) overlook many externalities. And thus, "common sense" is a dangerous path to follow in politics. And, as I said earlier, is most often used as special pleading to allow a law which goes against one's principles, or which is based on concepts which are frightening if taken to their logical conclusions.

    As far as Mr. Paine is concerned, upsetting him does not trouble me unduly. He was quite an agitator, and not exactly a consistent political thinker. There is a reason he did not stay around to build the new nation but went off to agitate in France. Much as I respect the role he played, assuming he would disagree with my argument (which is not a given), it would not make me lose sleep.

    1. I should be more fair and say Mr. Paine was not an original political thinker, or a creator of new systems (what I meant by "consistent"). He was quite adept at polemics, and at popularizing the arguments of others (though at times in so doing he adopted positions that were not completely logically consistent). Not that there is anything wrong with such a role. I adore Mr. Bastiat, and he fulfilled essentially an identical role in arguing against economic follies in the France of his day. Though Bastiat, as he drew almost exclusively on a single school of thought, was more consistent.

      To be even more fair to Mr. Paine, even the original political thinkers of his era, be it in theory or practical matters, were not completely consistent either. Mr. Jefferson, though idolized by many libertarian types, made some bizarre suggestions now and then. (Some of which would make libertarians quite uncomfortable.) Mr. Madison was more consistent, especially in his political practice in office, but he too had occasional oddities in his thoughts.

      But, I suppose if we were to take the entire lifetime output of any thinker and bind it together, as is so often done with famous men, it would seem rather inconsistent, as people do change their minds and (hopefully) mature over time, so what was a certainty at 25 is seen as a falsehood at 40, or vice versa. I know looking back over my blog posts, going back only 6 years, some of those early posts make arguments I no longer support completely. My thoughts have not changed so dramatically I need to completely repudiate any of my old posts, but I definitely understand some things differently now than I did when I started in November 2007.

  3. I also think you misunderstand my argument. I do not say society cannot pass laws, I argue those laws must be based upon sound principles, not "common sense". As I said above, whenever I hear "use common sense" in a legal sense, it is being used to plead for a law which contradicts the principles of minimal government. Such as, when arguing that Kelo really is the logical outcome of eminent domain, and thus that legal principle is dangerous, we often hear "then legislators need to use common sense". However, as I argue repeatedly, if you give someone a power, they will use it, and if you establish a principle, even if you try to hedge it in with limitations, eventually it reaches its logical conclusion, despite all the effort to limit it with "common sense". Common sense would suggest allowing married couples to buy condoms is not the same as legalizing abortion, but Griswold grew into Roe, because of principles established in the first case, which inevitably grew to their logical conclusion. Similarly, allowing the government power of condemnation for any "public good" inevitably ended up with politicians condemning land for more taxable developments or projects that favored political patrons. Common sense restraints, which said they had to use the power for governmental purposes, did not limit it.

    And that is the reason I attack common sense, because it is so often used in special pleas to ignore principles and allow just one little common sense exception, or to allow an exception which shall be tempered with common sense, or any of a dozen other ways of phrasing it. I feel the need to point out again and again that principles trump common sense every time, and though no one likes to hear it that slipper slope is alive and well. Once a concept, a principle, an idea is conceded, it will eventually reach the logical limit of its implications, whether that fits with anyone's common sense or not.

    Maybe that was a bit more clear. I never know. Sometimes what seems clear to me is muddy to others, so I repeat myself, and write several different essays on the same topic, hoping that if I restate things a few ways maybe it will be more clear. Which is why I so often seem to be harping on a topic. It is not an effort to nag people, or some sort of obsession, it is because I always worry what I say in one way may be more clear said another, and so I write both, or maybe three or four variations, hoping that I do a good job in at least one.

  4. I think you’re an excellent writer and debater, Andrews, but in this case I don’t think it’s a question of not adequately explaining yourself or stating it the right way. I think it’s that you’re conflating common sense with discretion. You don’t want any wiggle room (i.e. discretion) left in the law that can be open to interpretation where we must then rely upon the common sense of those who will decide. I agree, ambiguity in the law is a dangerous thing, but there’s no way to avoid it entirely.

    You said laws should be based on principles, not common sense so let me ask this: Is the right to privacy a matter of principle or a matter of common sense? I would put it in the “principle” category, and yet that didn’t prevent the law from being subject to overly broad interpretation and abuse. So what’s that solution? Should we have no law at all with respect to privacy? Should we expand the law to thousands of pages like Obamacare to ensure that we cover every possible misinterpretation? Ultimately you MUST rely on people to apply the law with common sense, and the only way to do that is to put the power for those decisions in the hands of people who have demonstrated a grasp of common sense (i.e. not liberals). In both of the examples you cite (Roe and Kelo) the liberals had the majority opinion.

    Ultimately we are always dealing with human fallibility, and the laws are only as good as the public’s willingness to uphold them, even when they’re based strictly on principles.

    1. You may have a point, however if anyone is confusing common sense and discretion, then it is not I, but those who would argue that the use of common sense allows for greater discretionary power. My point is, laws must obey the principles of minimal government (at least ideally, obviously we are nowhere close tot hat now, so any change for the better is welcome). However, others argue, even in an ideal state, we can allow for other, more expansive laws, provided we "temper them with common sense". And so, common sense becomes a justification for discretionary powers, which is why I may seem to confuse the two, because one is used to justify the other in so many arguments.