Last week, the online magazine Muftah ran a thoughtful piece by Scott Williamson and Caroline Abadeer about “why Arab Spring protests successfully produced regime change in some countries but not in others.” As they see it,

Understanding the outcomes of the Arab Spring uprisings requires answering the three interlinked questions about the region’s unrest posed here. First, where did protests transform into uprisings that could sufficiently threaten the regime’s hold on power? We have argued monarchies and oil-wealthy regimes can erect more barriers to prevent protest escalation, and thereby protect the government. Next, we asked why militaries abandoned regimes in some countries where uprisings occurred, but cracked down violently on the opposition in others. We have suggested that a military tied to the regime by familial, tribal, ethnic, or sectarian connections would be more likely to support the regime. Finally, in cases where the military repressed the opposition, we asked why such repression was successful in some countries but not in others. Because resources are important in this regard, we have argued that oil-wealthy regimes were more likely to successfully repress their opponents, and that resources brought to bear by foreign powers for or against the regime could also have a significant impact on the outcome.

Their essay is grounded in careful study of relevant theory and the societies they describe, and the array of contingent effects they identify all seem plausible. Still, I wonder if the authors are too confident in the explanatory power of their discoveries. As it happens, the Arab Spring has largely followed gross patterns in democratization from the past century or so. Popular uprisings rarely occur in consolidated authoritarian regimes, and when they do, the regime usually survives. When authoritarian regimes break down, another autocracy usually ensues. In cases where an attempt at democracy does happen, it usually fails, either by military coup or by the ruling party’s unfair consolidation of power.

The rules of thumb I just described overlook a lot, including virtually all of the features that people who live in or closely follow politics in those societies would care deeply about. That gross simplification doesn’t make them wrong, though. In fact, their absurd simplicity may be a more accurate representation of the limits of our knowledge than the more elaborate maps we draw with the benefit of hindsight. Sometimes we can grasp the generalities but still struggle with the specifics.

This state of affairs is not unique to the social sciences. A while back, the Guardian carried a story about the problem of limestone rot in historic British buildings. As the piece described,

The gargoyles at York Minster are losing their grimaces, pinnacles are turning to powder at Lincoln Cathedral and Wells Cathedral in Somerset has already lost most of its beautiful statues on the west face. Hundreds of years worth of grime and British weather are taking their toll on these treasured historic buildings, with the limestone they are made from simply being eaten away.

Because these structures are treasured, scientists set to work on trying to learn more about this rot in hopes of finding ways to slow or stop it. Even in the supposedly more predictable world of the “natural” sciences, though, this puzzle turns out to be quite a challenge.

[Researchers] already know what makes limestone decay. Chemicals such as sulphur dioxide and nitrogen oxides from air pollution react with the stone to make it dissolve. This sometimes creates a hard, black, gypsum crust on the outside, leaving a soft, crumbly stone underneath. Road salt is a modern-day scourge, spraying on to the base of walls and eating into the stone. And rain, wind and snow can also cause problems, with winter freeze-thaw cycles forcing open cracks. But the manner in which limestone erodes is puzzling. “We often see a single block of limestone get hollowed out, while others around it remain fresh,” said Dr Viles. It is not clear what makes one block more vulnerable than another.

The struggles of these researchers who understand the relevant causal mechanisms much better than we political scientists do remind us that we should remain open to the possibility of constrained randomness. The odds of a revolutionary moment vary in grossly visible ways, but they are still just odds. As sailors and cyclists can tell you, sometimes a squall hits when the weatherman said it would almost certainly stay dry. That doesn’t mean the models behind that forecast were fundamentally flawed, and our ability to see in retrospect how that storm arose doesn’t always make future ones any more predictable. Maybe the scientists studying limestone rot have finally figured out what makes one block more vulnerable than another and can now accurately predict which stones and statues will go soonest. Given the limited state of our knowledge about human social dynamics and the extreme complexity of the systems involved, I am not optimistic that social scientists will soon achieve a similar level of understanding, and thus foresight, about the transformation of political institutions.

To be clear, I do not think that the kind of post hoc analysis in which Williamson and Abadeer engage is fruitless. On the contrary, after-the-fact process-tracing and comparative analysis, be it narrative or statistical, is fundamental to the development of new ideas about what causes the phenomena we study. We may not understand a lot, but we certainly understand a lot more than we did a few hundred years ago, and this repetitive and meandering interplay of deduction, prediction, and observation is why. We just need to be careful not to get too cozy with the stories we spin when we look backwards, to succumb to what Daniel Kahneman aptly calls “the illusion of understanding.” The real test of our discoveries’ explanatory power isn’t their ability to make sense of the cases from which they were constructed; it’s their ability to help anticipate the occurrence and outcomes of the next batch. If authors like Williamson and Abadeer really want to test the inferences they’re drawing from the Arab Spring, they should start telling us what those inferences foretell about the prospects for, and outcomes of, future tumult in that part of the world.

Personally, I remain optimistic about broad trends and uncertain of the details. Many of the authoritarian regimes in the Middle East and North Africa may still look firm, but that doesn’t mean their foundations aren’t rotting. When those blocks do visibly crumble, the same meso– and macro-level systemic forces that have been driving the spread of democratic institutions for a while will probably drive these societies in that direction, too. As with the Arab Spring, we can expect a lot of variation in the timing and details, and we can expect some reversions to authoritarian rule to follow, but nothing yet leads me to believe that the now-familiar rules of thumb have stopped working.