You’re sent back in time to the year 527 AD

Monday, May 21st, 2018

You’re sent back in time to the year 527 AD, Tyler Cowen posits:

Let’s assume you’re good enough at learning languages. Where would you pick? And why?

Bryan Caplan chooses Byzantium:

First of all, of course assuming you’re good at languages, Greek as a Western language would be easier. I think that is actually the biggest city in the Western world at the time. It’s the one where you’d still have at least a modest amount of Greek and Roman thought which has been preserved. Really center of civilization by that point.

That would be the place where you’re most likely to have smart people around — there’s things that you can do with your mind — and least likely to get ripped apart by barbarians.


The temptation to become a government adviser under those circumstances would be painfully high. As to whether I could actually find some role there where I would not be morally horrified is a tough call.

If I could get away with just being a teacher, if I have what I know, then to actually go and found a school and teach economics 1,300 years before the rise of modern economics and try to jump-start the Industrial Revolution and economic growth and social science and everything else. Emotionally, that would have by far the strongest pull on me.

If that weren’t available, then there’s room in business, banking, moneylending, shipping. I think I could learn those. Wouldn’t be thrilled. But it beats rowing an oar.


  1. Bob Sykes says:

    “at least a modest amount of Greek and Roman thought”

    At that point, the Romans still had the entire classical canon, and life in Constantinople was near the high point of Roman civilization. The plague and a little ice were just a couple of decades away, and in a hundred years or so the Muslims would come charging out of the desert. But, this was not a low point for the Roman Empire, it was almost reunited, and Byzantium was hundreds of years away.

  2. Kirk says:

    I’m rather cynical about the entire idea of “changing history” via the judicious application of an “enlightened one” time traveler. Ain’t gonna work, for ohsomanyreasons… Number one being, in order to just survive, let alone prosper and “change history”, you’re going to have to be able to plug yourself into society. Good luck, with that–The past truly is a different country, with different customs, values, and mores. Care to extrapolate how well you’d do, taking your current set of “racially enlightened” attitudes back just, oh, say… To the 1930s? Whites would likely ostracize you, blacks would be suspicious, and the whole mentality you possess would stick out like a sore thumb, were you to behave as you have been taught today–Even the little things, like saying “sir” to a black man as a white, would betray you. Then, too, imagine taking your racist assumptions back a few hundred years before the entire idea of racial inferiority was even articulated, along with the idea of “race” in the first damn place…? LOL.

    I’m not sanguine about anyone’s chances for survival, let alone being able to “change history”. Imagine trying to cope with the concepts of aristocratic privilege, in Europe or Japan–As a person trying to fit in as a commoner, how well would a modern do at fitting in with the entire idea of being automatically subservient in a milieu where the nobility could chop your head off or rape you at whim? Try to fit in as a member of the nobility or samurai classes, and then you’re going to have to be able to do those things, in order to fit in.

    As well, there are all the unwritten laws of the society that “everyone knows”. Byzantium, for example? Which faction do you pick, in the chariot races? Could you get away with demonstrating disinterest? Or, would that mark you as irrecoverably outre?

    There’s a lot we just don’t know, when it comes to what societies were like, back when. It shows when we try to puzzle out the mores and values of even a few generations previous to our own–Ever tripped over unspoken assumptions of your own, while talking to your grandparents? Now square or cube that, going back to ancient times. What got written down was not the reality; the reality was nearly all unwritten.

    We still don’t know for sure whether or not the Romans marched in step; there’s no mention of any of that in the literature, and for anyone who has ever tried to maneuver a mass of men in a military formation or a marching band, that question is one that is quite bothersome. You assume that they had to have, but the actual knowledge of how they did it…? Just isn’t there; it’s not mentioned in any of the learned tomes we have which come down to us from the Roman era. Is that an example of the unwritten, or did they just not do it?

    I think you would stick out like a sore thumb, as a time traveller, unless you feigned being a deaf-mute and mentally disabled, to boot.

  3. TRX says:

    For a long time, more of the Roman Empire spoke Greek at home than spoke Latin.

  4. Kirk says:

    I think a lot of this sort of hypothetical depends on a bunch of stuff we just don’t know enough about.

    The Greeks and Romans certainly had the basis for industrialization and the antecedents of modern technology; what they lacked was more in the arena of social software that would have rewarded and encouraged innovation and change. The question of why, exactly, they did not build and develop water-powered industrial plant is a huge one. We know that they had barge-mounted grain mills, but we also know that they didn’t extrapolate those techniques and tools to things like running stamping mills for ores and metal processing (or, at least, the evidence for such is non-existent in my readings…). The Romans had extensive factory infrastructure and mass-production for military items, but it was all hand-work performed by slaves.

    Answering these questions is something we just don’t have the information to even form a good opinion on–It’s all conjecture, and most of it badly done, all the way down. Why did it take until the 19th Century for the industrial revolution to take place? The Greeks and Romans both knew of petroleum, and even apparently weaponized it, so why didn’t someone make the inferential leap to saying “Hey, why don’t we sell this crap as a lighting source…?”. Likewise, the Chinese… They were using bamboo to pipe natural gas into homes for fuel and lighting, but that technology was never developed past that primitive point to anything really significant, in terms of industry. Why?

    The imponderables here are the things a time-travel hypothesis would have to answer. Did the ideas simply not occur to anyone, or was it that the social milieu didn’t allow for these things to develop…?

    Along with this, someone needs to answer the questions for why so many inventions and innovations seem to happen simultaneously in different locations at about the same time. The crossbow being one of those ideas… What causes that to happen? Is it a “hundredth monkey” thing, a case of “the times are right”, or something else?

    There are a lot of interesting questions here that we just don’t have good answers for, and which our theoretical time-travel victim would need to know in order to effect any changes in the historical timeline.

    I don’t think that it’s necessarily possible to really effect major change, given how much of human social behavior is a concatenation of social behavior and technology. How would you go from Point “A”, where there is no real long-distance communication past the range of your voice, straight to Point “M”, where the modern sort of “smart” cell phone is common, without the intervening social points of the telegraph, wired telephone, and all that? Care to imagine the reaction, were you to tell a 19th Century adult that you wanted to give their kids essentially unfettered access to talk to anyone in the world, in privacy…? Or, the social upheaval, in terms of courting and marriage, were you to suddenly lift the boundaries of Victorian mores and values, the way that the bicycle and automobile did?

    Technology and society go hand-in-hand; I don’t think you could graft even the essential basics of modern technological society onto an ancient culture without first having to virtually destroy it, and that introducing a lot of what makes us “modern” would probably destroy an awful lot of what those societies were founded upon…

  5. Adar says:

    Lead sailing expeditions beyond the Pillars of Hercules westward. You might find something.

  6. Kirk makes a good point about not getting killed by the (temporal) locals, but I also wonder how a modern person’s immune system would handle the many pathogens unique to some time and place in the distant past. Depending on when and where we were positing, the results could be anything from mere illness to a quick death.

  7. Kirk, are you familiar with the concept of “Steam Engine Time?” Simplified, it’s the suggestion that any given technological innovation has a massive web of necessary conceptual, practical, and social factors that must be fulfilled for it to come into existence, and that once they do the idea requires only for inventors to recognized and act on the possibility. Thus, several people independently inventing the steam engine (or practically anything else you care to name) almost simultaneously.

    I think there are probably some high-leverage things a time traveler could do at select points in history to bring about an early transition to industrial civilization, but I think they’re things lower in the stack than actual physical technologies. “Modern” (i.e. 17th and 18th century) banking and investment concepts, the idea of the joint stock company, maybe introduce water-droplet microscopes and get people thinking about micro-biology, quite a lot of naval architecture knowledge that would be readily applicable and profitable. There’s probably no (purely intellectual) reason you couldn’t have introduced everything in mathematics from 0 to calculus to group theory to the ancient Greeks, or the thermodynamics essential to so many industrial technologies.

    Of course, once you make such a change, even assuming you don’t die of disease or running afoul of the cultural gulf, everything that follows will look almost completely (and unpredictably) different from our timeline.

  8. Albion says:

    Quite possibly your health and size would make one stand out more than you would like, and you would have I believe to get used to the most appalling smells that the locals took for granted. Your smell might repulse them, too.

    Also, what could you say that would not mark you out as lunatic? One day men and women will fly in metal tubes? At the same time you can talk to anyone in the world and they will hear you instantly, and all while watching moving pictures of sports events from multiple angles?

  9. Kirk says:


    I’m familiar with the idea, but I don’t think I’ve ever really seen it articulated as that particular construct.

    As to the immunity thing… Consider this: Your modern immune system is attuned to more evolved versions of disease than the ancients, and what your immune system treats as no big deal would probably produce pandemic results in an ancient setting. We see this all the time, in the real modern world–Look at what the Nepalese peacekeepers managed to do to Haiti, with their version of cholera, for an example.

    Hell, imagine taking a modern variety of the flu back in time to a place where there was no evolved immunity to it… Although, that could make for an explanation of where some of these unexplained plagues in the ancient world came from. “Hey, we’re going back in time to see all the historically significant developments in the Byzantine Empire…”. “Oh… Uh, yeah… That pandemic which our new timeline calls the Plague of Justinian, that set Islam up for success…? That was us; the flowering of the Byzantine Empire didn’t happen, ‘cos we done killed all the people that made it happen…”.

  10. It’s a great point that that goes both ways, and there’s some fantastic SF story potential there if someone wants to jump on it.

    With regards to the old-timers’ effect on the time traveler, though, I’m not so sure that having immunity to modern forms of a disease grants immunity to old strains. It seems more like it would be a sliding scale as you go back in time, becoming more and more lethal to the time traveler as the microbial fauna had less and less overlap with what they developed in. Caveat that I’m no microbiologist and this could easily be wrong. I’m interested enough that I’m going to pose the question to a friend of mine who is. I’ll post an answer if I get one.

  11. Kirk says:

    I’d be interested to hear what your friend has to say on that issue… I don’t know that anyone has really done much research on that issue, or that one even really could…

    I do know from my reading that there’s a process of adaptation which goes on with any new disease; syphilis, for example, has become far less destructive as the host/disease adaptation process goes on–As someone once observed, it’s a damned stupid parasite that kills the host it lives off of…

    So, maybe you’d encounter a much more damaging version of the disease you’re immune to, in its attenuated form, and die because of that? I don’t know enough to say, and maybe nobody does, as we haven’t “run the experiment”. Although, you could say we’ve done that in a somewhat analogous form, when a new disease is brought into an unexposed population like the natives here in North America.

    Kinda makes you wonder, though… What if we’re seeing signs of time travel with some of these disease pandemics like what killed off all the Central American native populations after Cortes initial successes against the Aztecs? It’d be darkly humorous if that was a reality–Historical time-traveller goes back to observe their favorite hobby-horse, and manages to kill off their own history by doing so.

    It’d be like going back to observe WWI as it happened, and taking some future pandemic-capable disease with you, and instead of observing the start of the new world order, you inadvertently managed to kill off the people who created all that cool stuff with the Spanish Influenza Epidemic.

    Could explain why we don’t have time travel; anyone who actually manages to invent it goes back and forth in time, spreading disease, and manages to kill off everyone who would lead to time travel being invented…

  12. William Newman says:

    I don’t think Caplan is being realistic about the market value of teaching economics. Economics not a vacuous fake field, so the idea is not as absurd as it could be. But the idea still seems deeply unrealistic. I have taken some battlefield tours guided by an army operations research guy, and he is sharp and probably suited to teach courses in e.g. logistics-related things, which are not vacuous, and which are about as applicable to Byzantium as economics. But how many people really need such courses, and how easy is it to establish your qualifications so that those people’s tuition adds up to a good wage?

    If you can get over the initial hurdles (language, xenophobia, dysentery…) without career-ending misfortune, and get some contacts and a month or so of savings, I think it would be a lot more promising to try to sell various things that we moderns take for granted. Make a knit cap or a pair of knit socks. Learn a locally available musical instrument well enough to adapt catchy modern musical melody and/or harmony and/or rhythms: anything that made a good movie score (Toccata in D minor intro, or the Mozart concerto used for Elvira Madigan, or Scott Joplin) might be worth trying. Chase down a serious surveyor, who judging from the archaeological tidbits I’ve heard of will likely be using trigonometry, and will not be using Arabic numerals, and see whether you can cut a deal to ease his pain.

    Also, if one could avoid the various social gotchas that tend to grow around serious gambling, elementary probability theory would give any modern from a mathematical field like economics a serious advantage in gambling with cards or dice or wheels or other inanimate objects (as opposed to gambling on gladiators or racing or whatever). And, if you don’t want to do the gambling yourself, I bet you’d have a much better chance of getting people to pay you to teach that than getting people to pay you to teach economics.

    With a year or so of savings (and, ideally, a reputation that helps you get a patron to buy the expensive materials), you might try selling some I’m-a-savant publicity prestige sponsorship package based on flashy or profound eighteenth century and nineteenth century tech: Leyden jars, man-carrying hot-air balloons, solar spectroscopy, the galvanic frog leg contraction trick, Pasteurization, or (assuming there’s interest in breeding farm animals or war/racing/whatever specialist horses) even Mendelian genetics. None of those are sure winners, but all seem more promising than trying to sell economics or logistics or marketing or mnemonic methods or similar nonvacuous but specialized and shallow things.

    And if none of *that* floats your boat, and you really want to teach theory, I think even if you’re an economist, you might have a better chance of getting supported for teaching what you know of stuff related to Newtonian mechanics — mechanics itself, plus calculus, applications to planetary observations, and various tabletop demos. It is a deeper field with more sharp knowledge, it is more obviously widely applicable, and whether you have ten minutes to do it or ten weeks to do it you have a much better chance of demonstrating to a prospective student that you know things which are nontrivial and potentially useful.

  13. Kirk says:

    No matter what, it would be an interesting experiment to observe: “Time travel and historical acceleration: Can it work?”.

    Do not, however, look to me volunteering to run the thing in the field. I remain convinced that there are a bunch of stumbling points for all of it, that we just don’t see.

    I think your best bet, were you to want to try this out, would be to take yourself and a bunch of your friends back to some isolated part of the world, and then set your own society up.

    Which, come to think of it, may explain the Denisovians or the Tocharians…

  14. Chedolf says:

    … there’s some fantastic SF story potential there …

    Lest Darkness Fall by L. Sprague de Camp. “An archaeologist is transported from Rome, in the time of Mussolini, to the 6th century and tries to prevent the fall of the Roman Empire.”

  15. Graham says:

    I was a huge fan of Lest Darkness Fall, and any other fiction that involved either a time traveller altering history for the better or someone else preventing the fall of Rome.

    For better or worse, I’ve become more fatalist. Save your own civilization before it falls, or resign yourself to carrying the torch or rebuilding later.

    That and I slipped out of the idea that the fall of Rome was an unaccountable, preventable development rather than being both the likely end of any civilization and the definable product of multiple forces at play in the times. I’ll leave it to continuing historical debate which ones these were, although additional work was done in the 2000s.

    If anyone watched Stargate SG1, there was a moment at which Daniel Jackson throws away a line about how if it hadn’t been for the Dark Ages, man would have been exploring the stars centuries ago. It’s a seductive line and related to the idea behind Lest Darkness Fall, but it has some of the qualities of “if my granny had wheels she’d be a wagon.”

    That and I tend to think Mark Twain was more right than deCamp. Any of us who tried this would end up being the Connecticut Yankee in King Arthur’s Court.

    Not that time travel alternate history is not fascinating. I’m still haunted by some of Poul Anderson’s Time Patrol stories — Delenda Est and The Sorrows of Odin the Goth, for two.

  16. Kirk says:

    Given the way Rome conducted itself, and the stultifying manner in which the Imperial bureaucracy ran everything…? I’m not so sure that Rome’s fall was a bad thing. Actually, I think it was necessary, because it cleared out all the dead wood and weeds that were holding everything back.

    As well, the Roman Empire’s preemption of all things defense-related? Along with the upper-class reluctance to participate in the defenses…? That left all of Europe unable to take care of its own defenses when the barbarians came knocking at the gates. Had the Gauls been left alone, instead of domesticated like so many farm animals…? Odds are, the great migrations would have hit more than just token resistance at the borders. Roman Imperial neglect of the military and defenses along the borders was immoral to the extreme–On the one hand, they denied the conquered citizenry of Roman Europe the ability to defend themselves, and then abnegated Imperial responsibility to do the job. The invaders found little effective resistance in Roman Europe, and indeed, also found that they were welcomed due to the extremely punitive tax structure of Rome being gone…

    When you look at it in a certain light, the whole thing is amazingly similar to what we have going on today, only with the US cast as the protector that’s enabled European bad ideas about such things to flourish. What’s that line about history repeating itself, first time as tragedy and second time as farce…?

    I think we’re well into the “farce” stage of things, as the Euros enable their own destruction behind our shield. Maybe NATO was a really bad idea, and we should have let the Soviets have the place–The Western European nations would likely have a better sense of what they’re risking, and after the inevitable fall of the Soviets, they’d be going through the same sort of semi-Renaissance that Eastern Europe is going through…

  17. Graham says:


    My current impression is that late antique Rome indeed had [by ancient standards] a larger bureaucracy than it could handle, although you could see why it evolved out of the failure of the previous state model in the crisis of the 3rd century. Much larger and more costly army than the early empire too.

    If anything, late Rome could be used as an example of maintaining huge, expensive, normally effective military forces that are still not quite equal to the threats facing them, and used in such a way as to neglect ultimately more critical threats that work in the background. Plus a degree of rust out towards the end as the tax base shrinks, ultimately reducing the effectiveness too. Hmmm.

    They moved to a border troops/mobile reserve model for reasons, and it’s not clear to me whether that weakened the overall Rhine defenses enough to by itself explain what happened in 405-6, but maybe.

    They definitely ended up in a position where they had ceded so much territory within the western empire to German federate rule that they had no tax base to maintain their military capacity to subdue those same Germans.

    On the other hand the East had some resilience. IIRC, they massacred all the German troops in their army and replaced them with citizen Isaurians.

    Somewhere not too long ago I read this exchange between Bryan Ward-Perkins and Peter Heather, who did two of the more interesting books of the 2000s

  18. Helsing says:

    Bryan Caplan is fantasizing about teaching libertarian economics to the Byzantines?

    But as a Jew, he would be banned from any such activities.

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