Wednesday, March 11, 2009

Single Etiology Theory

One of the philosophical errors that I complain about a lot is single-etiology theory. Single etiology theory is the theory than an event has a single cause, an etiology, rather than a huge host of different causal factors. Most ancient Western theories of causation imagined that every event had multiple causes, and typically thought that there were several different kinds of cause for any event. In Aristotle’s picture of causation, every event had at least 3 causes, a material cause, a formal cause, and an efficient cause, and it was normal to have final causes as well if living creatures were involved, and normal for an event to have a long series of related efficient causes. In Galen’s theory of medicine, the health of the body was importantly related to the balance of 4 humors in the body, and many, many factors affected the overall balance of the humors. That meant that if a body was sick, it was because the humors were out of balance, and even if one factor was the main cause of the imbalance, many other factors were also part of the overall picture, and you could attempt to treat the problem by addressing any of the factors, or often many of them in combination. A similar picture dominated in China, imagining balancing of yin and yang, or of multiple forms of chi, or of the 5 elemental processes to be a fairly holistic phenomena, so that natural occurences, especially in medicine, tend to have many different distinct causes. In India, even from ancient times, there was a lot of formal complexity to the debates on the nature of causation. It is normal in ancient India to make fine distinctions between causes, correlations, conditions, and other kinds of factors. The Buddhists, for example, largely restrict their claims to co-arising dependent factors. Still, if we think of these as all being species of conditioning factors, any given event is likely to have a whole host of conditioning factors of different kinds.

But Islamic medicine under Ibn Sina and Ibn Zuhr championed the notion that some diseases like stridor or tuberculosis or STDs had a single cause, as opposed to being caused by many factors together as in Galen’s humorism. There is something right about these cases, if we ask why does ‘Ali have an STD, then saying because he slept with Aisha who has the STD is more salient than saying, because he was in overall poor health when he contracted it. In that sense, sex looks like “the” cause of STDs. But, even here this isn’t the full story. Sex with a carrier is often a necessary condition of contracting an STD as well as being “a” cause, but this doesn’t make it “the” cause of the STD, because it isn’t a sufficient condition. Perhaps, Hussein slept with Aisha too, but didn’t contract the STD, and if we ask why did ‘Ali contract it but not Hussein, the answer might turn on issues of overall health, or perhaps on a combination of many factors. Even if sexual contact with a STD carrier is in some sense the “main” cause of contracting an STD, it still isn’t “the” cause, much less “the sole” cause.

Nonetheless, single etiology theory, the idea that some events have a single cause, or at least a single most proximate efficient cause with perhaps a chain of causation stretching into the past, became more and more popular in the West, in medicine and in other sciences over the centuries between the 14th and 20th. Mechanist philosophies of nature struggled against Vitalist philosophies of nature and Westerns came to think of many things as being more like machines than living entities: the stars, the earth, the human body, other plants and animals, even nations and societies. And the machine metaphors for everything made it more plausible to think of events as having a single etiology, a “the” cause. After all, that is how machines are often designed to work; this gear causes another gear to turn which causes a shaft to turn which moves the second hand on the clock. In this theory, causation happens in chains, but in one on one relations with each effect having a single cause or a single chain of causes.

Single etiology theory also fit nicely with the increased emphasis on individual selves in social philosophy, during modernity. If events have a single cause, then maybe a single person is to blame when things go wrong, the cause of the problem. And maybe a single person gets the glory when things go right too, a great artist or politician. Personal responsibility is a sort of social correlate of a metaphysics of causation where events have a single cause. And if the divine hierarchy of divinely ordained kings and bishops no longer seems plausible, perhaps the machine hierarchy of cogs and regulators can replace it, where the chain of causation, has its analogs in the chain of command and the chain of responsibility.

By the 19th century, Europeans routinely talked as if events had a single cause, rather than a host of causal factors, and this came to seem normal rather than seeming like a philosophical position. The idea that events typically have a single cause becomes a cornerstone of the official medical philosophy of the US in the 19th and 20th centuries, although the “holistic” approach that events typically have many causes has certainly reclaimed some respectability in the last few decades. But single etiology theory pervades many levels of American thinking, from our “folk” metaphysics when we are speaking loosely, to our most careful formalizations of the metaphysics of causation. It is a frequent unconscious assumption of our science and policies, although physics in particular has been backing away from single-etiology theory during the 20th century. Sometimes you can push people to admit that when they say “the cause” they mean “the main cause,” but it is a philosophical error of great importance to assume that events always have even a “main” cause. I hold that most events have a whole host of causal factors, often of quite different kinds. Each event happens the way it does because of many, many interlocking factors. Change any one factor and the event would turn out differently, at least a little bit differently, and often quite a bit differently. Single etiology theory is a decent simplification of the truth when an event really does have a single main cause (which does happen sometimes), or a single very relevant causal factor that has been overlooked or misunderstood. It works sometimes, or works well enough, and there are certainly success stories for single etiology theory. But it bollixes up the many, many situations in which many quite different causal factors are interacting to produce the overall event.

The fact that single-etiology theories of causation are extremely popular, but also are flawed, has a number of important consequences for our understanding of social collapse, and our adapting successfully to it. First, our usual sense of blame rests on an erroneous picture of causation and responsibility. What is “the” cause of our societal collapse? There is no one answer to this question, because there is no single sole cause, and probably not even a single main cause, but many, many causal factors combining to result in what is actually happening. The right causal story of our social collapse involves individual greed and fraud, the tensions built into growth economics, the arrogance and optimism of those who assumed we could keep growing on forever, the failures of the education system and the media to help people to understand, the power-hungriness of the elite, the patterns of generations, the biological impulse to overpopulate, and probably plenty more factors as well. The moral, the biological, the political, the economic, the historical, the social, and even the philosophical are all genuine parts of the causal story, and do not even form a single chain of efficient causation, but a vast web of interlocking causal factors. So who is to blame for our troubles? Well, many, many people and categories of people. Everyone shares the blame, but not everyone equally or all in the same way. Some people were definitely more causally influential than others, or more blameworthy in their influence, or influenced different parts of the long complex event of our collapse. Tim Geithner, Bernard Madoff, and your mother are all to blame, but they are not all equally to blame.

Second, when we are trying to plan our responses to problems, we need to understand that societies and economies are more like living things than they are like complex machines, in that events usually have many causes. Imagining that we can control the rate of change of a Consumer Price Index, simply by manipulating the interest rate on overnight debt in line with the Taylor Rule, is a philosophical error (misunderstanding the nature of causation) even before it is an error in economics or monetary policy. Interest rates are an important causal factor in the change of a CPI, but a little reflection shows that they aren’t the only important factor, and that means that even if they are the main factor under many circumstances, they aren’t the sole cause, or a sufficient cause, and thus aren’t the main factor under all circumstances. Often manipulating overnight interest rates will succeed in manipulating CPIs, but not always, and not when it is most important. And that is just one example. Our economics, our medicine, and often our own attempts at adaptation frequently involve erroneously exaggerating the importance of one causal factor, because we think of it as “the” cause of the problem, rather than “a” cause of the problem. This is just a common error in our culture, because of the tenor of philosophy over the last few centuries. Just as holistic medicine struggles against single etiology theory in medical philosophy, so a holistic psychology, holistic economics, and holistic politics need to struggle against single etiology theory in psychology, economics, or politics. Human psyches do not work like dominoes, with causal chains falling neatly in rows and orders, they are deeply interconnected meshes of causal factors, and so are economies, and political systems.

Third, holistic lifestyle adaptations need to struggle against single-etiology theory in lifestyle adaptation. Our medical system is going to collapse, and that means you need to plan for problems with medical care in the future. And that means you should address your medical situation holistically, thinking about your particular problems or issues, but also you should address the causal factors that relate to them, and whatever your issues, diet, exercise, stress, exposure to toxins, your access to preventative medicine, etc are probably among the causal factors. But that means you need to adapt how you eat, where you buy your food, how you spend your time, how you think about your life, etc. Each strand of adaptation will tug on the surrounding strands of our lifestyle, and that is to be expected because our lives are the product of the interconnection of the many, many factors that cause our lives to be as they are. Giving up on single etiology theory means that addressing most problems honestly involves revising whole systems, rather than making a single change and feeling that we are done, because no single part of the system is wholly to blame, rather the system as a whole is the problem to be confronted.


  1. Excellent post - many people already cannot afford to pay to visit the doctor or dentist and are looking to simple home-made recipes to help their well-being.

  2. "I been caught thinkin, once, when I was five!"

    Whoops, sorry, segued into late-90's alternapop. Anyway. The thing that frustrates me so greatly about single etiology theory--from the perspective of teaching a Critical Thinking class--is how easy it makes being both right and wrong. Yeah, that should be contradictory, but it isn't.

    As you point out, and as I take incredible pains to discuss in my class, causation is almost never straightforward. But nearly everything in our current society is geared towards believing that it is simple--that for any effect, there is one (and only one, or at least one main) cause. So it's *easy* to find the cause of any problem--in effect, it's a recipe for scapegoating. What's the cause of our current economic meltdown? Loose regulation. Or Greenspan. Or the Republicans. Or the Democrats. Once any individual settles on The Cause, they stop. They ignore the complexities, the ways that all of this and more were at play--pointedly, including their own complicity, which is almost certainly there somewhere. It's ready-made scapegoating.

    Just as frustratingly from the other direction, ignoring complex causal structures also makes it very difficult to be right. No, it wasn't the Republicans fault!--look at the role that Fannie & Freddie played! It couldn't be the fault of scurilous mortgage lenders--look at all the people who got in over their heads and should've known better! If you're looking for only one cause, you'll never find one, nothing will ever satisfy that goal (which might be part of the point). This is most annoying in places like looking for the "cause" of autism. Everything we know about autism just screams multiple causes, but that doesn't satisfy the medical single etiology methodology. So instead, lead after lead is kicked out when it can't be shown to be "significant" or "important" in the causal structure. Well, there probably isn't a single significant cause, or anything like it. ARGH!

  3. Yeah, I increasingly think that the metaphysics of causation is deeply linked to social ideas of responsibility. If our actions are caused by something external, say God's will, or genes+upbringing, or the incentives of the economic system, then we can feel free from direct responsibility for our actions, we can blame the system instead. But if we locate the cause of problems inside persons, then well, maybe we can shift the blame to some OTHER person, and again feel free from direct personal responsibility for events we disapprove of. Sartre thinks humans will dodge the pain of their own freedom and responsibility in anyway they can. If we go to multiple causation theory, then we are almost never FULLY to blame, but we are almost always PARTLY to blame. But how do we wrap a justice system around that? Who do you sue when a dozen different companies and federal agencies are each partly responsible for a food contaimination case? I think here our ethical pictures are conditioning our metaphysical picture.