Is this a fair description of your disagreement re the 90% argument?
Daniel thinks that a 90% reduction in the population of a civilization corresponds to a ~90% reduction in their power/influentialness. Because the Americans so greatly outnumbered the Spanish, this ten-fold reduction in power/influentialness doesn’t much alter the conclusion.
Matthew thinks that a 90% reduction in the population of a civilization means that “you don’t really have a civilization”, which I interpret to mean something like a ~99.9%+ reduction in the power/influentialness of a civilization, which occurs mainly through a reduction in their ability to coordinate (e.g. “chain of command in ruins”). This is significant enough to undermine the main conclusion.
If this is accurate, would a historical survey of the power/influentialness of civilisations after they lose 90% of the population (inasmuch as these cases exist) resolve the disagreement?
For my part, I think you summarized my position fairly well. However, after thinking about this argument for another few days, I have more points to add.
Disease seems especially likely to cause coordination failures since it’s an internal threat rather than an external threat (which unlike internal threats, tend to unite empires). We can compare the effects of the smallpox epidemic in the Aztec and Inca empires alongside other historical diseases during wartime, such as the Plauge of Athens which arguably is what caused Athens to lose the Peloponnesian War.
Along these same lines, the Aztec/Inca didn’t have any germ theory of disease, and therefore didn’t understand what was going on. They may have thought that the gods were punishing them for some reason, and therefore they probably spent a lot of time blaming random groups for the catastrophe. We can contrast these circumstances to eg. the Paraguayan War which killed up to 90% of the male population, but people probably had a much better idea what was going on and who was to blame, so I expect that the surviving population had an easier time coordinating.
A large chunk of the remaining population likely had some sort of disability. Think of what would happen if you got measles and smallpox in the same two year window: even if you survived it probably wouldn’t look good. This means that the pure death rate is an underestimate of the impact of a disease. The Aztecs, for whom “only” 40 percent died of disease, were still greatly affected
It killed many of its victims outright, particularly infants and young children. Many other adults were incapacitated by the disease – because they were either sick themselves, caring for sick relatives and neighbors, or simply lost the will to resist the Spaniards as they saw disease ravage those around them. Finally, people could no longer tend to their crops, leading to widespread famine, further weakening the immune systems of survivors of the epidemic. [...] a third of those afflicted with the disease typically develop blindness.
I accept that these points are evidence in your favor. Here are some more of my own:
--Smallpox didn’t hit the Aztecs until Cortes had already killed the Emperor and allied with the Tlaxcalans, if I’m reading these summaries correctly. (I really should go read the actual books...) So it seems that Cortes did get really far on the path towards victory without the help of disease. More importantly, there doesn’t seem to be any important difference in how people treated Cortes before or after the disease. They took him very seriously, underestimated him, put too much trust in him, allied with him, etc. before the disease was a factor.
--When Pizarro arrived in Inca lands, the disease had already swept through, if I’m reading these stories right. So the period of most chaos and uncertainty was over; people were rebuilding and re-organizing.
--Also, it wasn’t actually a 90% reduction in population. It was more like a 50% reduction at the time, if I am remembering right. (Later epidemics would cause further damage, so collectively they were worse than any other plague in history.) This is comparable to e.g. the Black Death in Europe, no? But the Black Death didn’t result in the collapse of most civilizations who went through it, nor did it result in random small groups of adventurers taking over governments, I predict. (I haven’t actually read up on the history of it)
The Plague of Justinian is possibly responsible for the failure of the Roman Empire to reunite (Justinian had reconquered Italy and if he was able to secure those holdings European history might look more like Chinese history). Later iterations of the plague might have been responsible for the rise of the Muslim empires. https://en.wikipedia.org/wiki/Plague_of_Justinianhttps://pubmed.ncbi.nlm.nih.gov/22992565/
Interesting, thanks! Still though, it’s not like the Roman Empire got taken over by some wandering band of 1,000 men during the plague. My position is not that plagues aren’t important, but rather that they aren’t so overwhelmingly important that the factors I mentioned (tech, cunning/experience) aren’t also very important.
Thanks Alexis, this seems like an accurate description to me. Strong-upvoted, partly because I want to reward people for doing these sorts of summary-and-distillation stuff.
As for your question, hmm, I’m not sure. I tentatively say yes, but my hesitations are (1) cases where 90% of the population dies are probably very rare, and (2) how would we measure power anyway? Presumably most civilizations that lose 90% of their population do end up conquered by someone else pretty quickly, since most civilizations aren’t 10x more powerful than all their neighbors.
I think the crux is this business about the chain of command. Cortez and Pizarro succeeded by getting Americans to ally with them and/or obey them. The crux is, would they have been able to do this as well or mostly as well without the disease? I think that reading a bunch of books on what happened might more or less answer this question.
For example, maybe the books will say that the general disarray caused by the disease created a sense of desperation and confusion in the people which led them to be open to the conquistador’s proposals when otherwise they would have dismissed them. In which case, I concede defeat in this disagreement. Or maybe the books will say that if only the conquistadors had been outnumbered even more, they would have lost.
But what I predict is that the books will say that, for the most part, the reasons why people allied with Cortes and Pizarro had more to do with non-disease considerations: “Here is this obviously powerful representative of an obviously powerful faraway empire, wielding intriguing technology that we could benefit from. There is our hated enemy, Tenochtitlan, who has been oppressing us for decades. Now is our chance to turn the tables on our oppressors!” Similarly, I predict that the reason why the emperors allowed the conquistadors to get close enough to ambush them have little to do with disease and more to do with, well, just not predicting that the conquistadors would have the will or capability to do that. Moreover I predict that adding even more native warriors (due to the disease not happening) wouldn’t have caused the conquistadors to lose. After all, roughly half of those warriors would be added to the conquistador’s side...
So I highly recommend that someone who doesn’t have a dog in this fight go read some books on Cortes and Pizarro and then report back!
Update: I do think it would be good to look at the Black Death in Europe and see whether there were similar political “upsets” where a small group of outsiders took over a large region in the turmoil. I predict that there mostly weren’t; if it turns out this did happen a fair amount, then I agree that is good evidence that disease was really important.
Is this a fair description of your disagreement re the 90% argument?
Daniel thinks that a 90% reduction in the population of a civilization corresponds to a ~90% reduction in their power/influentialness. Because the Americans so greatly outnumbered the Spanish, this ten-fold reduction in power/influentialness doesn’t much alter the conclusion.
Matthew thinks that a 90% reduction in the population of a civilization means that “you don’t really have a civilization”, which I interpret to mean something like a ~99.9%+ reduction in the power/influentialness of a civilization, which occurs mainly through a reduction in their ability to coordinate (e.g. “chain of command in ruins”). This is significant enough to undermine the main conclusion.
If this is accurate, would a historical survey of the power/influentialness of civilisations after they lose 90% of the population (inasmuch as these cases exist) resolve the disagreement?
For my part, I think you summarized my position fairly well. However, after thinking about this argument for another few days, I have more points to add.
Disease seems especially likely to cause coordination failures since it’s an internal threat rather than an external threat (which unlike internal threats, tend to unite empires). We can compare the effects of the smallpox epidemic in the Aztec and Inca empires alongside other historical diseases during wartime, such as the Plauge of Athens which arguably is what caused Athens to lose the Peloponnesian War.
Along these same lines, the Aztec/Inca didn’t have any germ theory of disease, and therefore didn’t understand what was going on. They may have thought that the gods were punishing them for some reason, and therefore they probably spent a lot of time blaming random groups for the catastrophe. We can contrast these circumstances to eg. the Paraguayan War which killed up to 90% of the male population, but people probably had a much better idea what was going on and who was to blame, so I expect that the surviving population had an easier time coordinating.
A large chunk of the remaining population likely had some sort of disability. Think of what would happen if you got measles and smallpox in the same two year window: even if you survived it probably wouldn’t look good. This means that the pure death rate is an underestimate of the impact of a disease. The Aztecs, for whom “only” 40 percent died of disease, were still greatly affected
I accept that these points are evidence in your favor. Here are some more of my own:
--Smallpox didn’t hit the Aztecs until Cortes had already killed the Emperor and allied with the Tlaxcalans, if I’m reading these summaries correctly. (I really should go read the actual books...) So it seems that Cortes did get really far on the path towards victory without the help of disease. More importantly, there doesn’t seem to be any important difference in how people treated Cortes before or after the disease. They took him very seriously, underestimated him, put too much trust in him, allied with him, etc. before the disease was a factor.
--When Pizarro arrived in Inca lands, the disease had already swept through, if I’m reading these stories right. So the period of most chaos and uncertainty was over; people were rebuilding and re-organizing.
--Also, it wasn’t actually a 90% reduction in population. It was more like a 50% reduction at the time, if I am remembering right. (Later epidemics would cause further damage, so collectively they were worse than any other plague in history.) This is comparable to e.g. the Black Death in Europe, no? But the Black Death didn’t result in the collapse of most civilizations who went through it, nor did it result in random small groups of adventurers taking over governments, I predict. (I haven’t actually read up on the history of it)
The Plague of Justinian is possibly responsible for the failure of the Roman Empire to reunite (Justinian had reconquered Italy and if he was able to secure those holdings European history might look more like Chinese history). Later iterations of the plague might have been responsible for the rise of the Muslim empires. https://en.wikipedia.org/wiki/Plague_of_Justinian https://pubmed.ncbi.nlm.nih.gov/22992565/
Interesting, thanks! Still though, it’s not like the Roman Empire got taken over by some wandering band of 1,000 men during the plague. My position is not that plagues aren’t important, but rather that they aren’t so overwhelmingly important that the factors I mentioned (tech, cunning/experience) aren’t also very important.
Thanks Alexis, this seems like an accurate description to me. Strong-upvoted, partly because I want to reward people for doing these sorts of summary-and-distillation stuff.
As for your question, hmm, I’m not sure. I tentatively say yes, but my hesitations are (1) cases where 90% of the population dies are probably very rare, and (2) how would we measure power anyway? Presumably most civilizations that lose 90% of their population do end up conquered by someone else pretty quickly, since most civilizations aren’t 10x more powerful than all their neighbors.
I think the crux is this business about the chain of command. Cortez and Pizarro succeeded by getting Americans to ally with them and/or obey them. The crux is, would they have been able to do this as well or mostly as well without the disease? I think that reading a bunch of books on what happened might more or less answer this question.
For example, maybe the books will say that the general disarray caused by the disease created a sense of desperation and confusion in the people which led them to be open to the conquistador’s proposals when otherwise they would have dismissed them. In which case, I concede defeat in this disagreement. Or maybe the books will say that if only the conquistadors had been outnumbered even more, they would have lost.
But what I predict is that the books will say that, for the most part, the reasons why people allied with Cortes and Pizarro had more to do with non-disease considerations: “Here is this obviously powerful representative of an obviously powerful faraway empire, wielding intriguing technology that we could benefit from. There is our hated enemy, Tenochtitlan, who has been oppressing us for decades. Now is our chance to turn the tables on our oppressors!” Similarly, I predict that the reason why the emperors allowed the conquistadors to get close enough to ambush them have little to do with disease and more to do with, well, just not predicting that the conquistadors would have the will or capability to do that. Moreover I predict that adding even more native warriors (due to the disease not happening) wouldn’t have caused the conquistadors to lose. After all, roughly half of those warriors would be added to the conquistador’s side...
So I highly recommend that someone who doesn’t have a dog in this fight go read some books on Cortes and Pizarro and then report back!
Update: I do think it would be good to look at the Black Death in Europe and see whether there were similar political “upsets” where a small group of outsiders took over a large region in the turmoil. I predict that there mostly weren’t; if it turns out this did happen a fair amount, then I agree that is good evidence that disease was really important.