Take, for instance, Chinggis Khan (born Temujin; I am going to use Temujin here to mean the man himself and Chinggis Khan to mean his impact as a ruler once the Mongols were fully united). The conditions for Chinggis Khan were not new in 1158; the basic technological factors with made the Steppe way of war possible had existed in the Eurasian Steppe for at least two thousand years by the time Temujin was born. Political fragmentation was also an important factor, but this was hardly the first time that nearby China had been politically fragmented (at the very least the periods 771-221BC, 220-280AD, 304-589 and 907 through to Temujin’s birth in 1158 all qualify) and the steppe had effectively always been politically fragmented. Our evidence for life on the steppe is limited (we’ll come back to this in a second) but by all appearances the key social institutions Temujin either relied on or dismantled were all centuries old at least at his birth.

What had been missing for all that time was Temujin. To buy into the strongest form of “cliodynamics” is to assume that the Steppe always would have produced a Temujin (in part because his impact is so massive that a “general law” of history which cannot predict an event of such titanic import is not actually a functional “general law”). And to be fair, it had produced nearly Temujins before: Attila, Seljuk, etc. But “nearly” here isn’t good enough because so many of the impacts of Chinggis Khan depend on the completeness of his conquests, on a single state interested in trade controlling the entire Eurasian Steppe without meaningful exception. The difference between Temujin and almost-Temujin (which is just basically “Jamukha”) is history-shatteringly tremendous, given that both gunpowder and the Black Death seem to have moved west on the roads that Chinggis opened and the subsequent closure of those routes after his empire fragmented seem to have been a major impetus towards European seaborne expansion.

Moreover, it is not at all clear that, absent Temujin in that particular moment – keeping in mind that Temujin hadn’t appeared in any other moment – that there would have inevitably risen a different Temujin sometime later. After all, for two millennia the steppe had not produced a Temujin and by 1158, the technological window for it to do so was already beginning to close as humans in the agrarian parts of the world (read: China) had already begun harnessing chemical energy in ways that would eventually come to rob the nomad of much of his strength. If Temujin dies as a boy – as he very well might have! – it is not at all clear he’d be replaced before that window closed; his most obvious near peer was Jamukha, but here personalities matter: Jamukha was committed to the old Mongol social hierarchy (this was part of why he and Temujin fell out) and was so unwilling to do the very things that made Chinggis Khan’s great success possible (obliterating clan distinctions and promoting based on merit rather than family pedigree). Jamukha could have been another Seljuk, but he could not have been another Chinggis Khan and in this case that would make all of the difference.

To get briefly into a bit of historical theory, Chinggis is an individual whose actions in life fundamentally altered many of what the “Annales School” of history would call the structures and mentalités of his (and subsequent) times. The Annales school likes to view history through a long duration lens (longue durée) and focus on big shaping structures like climate, geography, culture and so on. The difference between this and cliodynamics is that Annales thinkers propose to describe rather than predict, so it is not fatal to their method if there are occasional, sudden, unpredictable alterations to those underlying structures – indeed those are the moments which are most interesting. But it is fatal to a cliodynamics perspective, which does aim for prediction since “our prediction is absolutely right unless it is completely wrong” hardly inspires confidence and a “general law” of anything is only a “general law” in that it is generally applicable not merely to the past but also to the future.

In short, Chinggis Khan wasn’t a commodity; he couldn’t be replaced by any other Mongol warrior. And figures like that abound through history (for Roman history, it matters greatly for instance that Marius, Sulla, Pompey, Caesar and Octavian had very different personalities when they found themselves in a position to dominate the Republic with military force). Moreover, the figures like that who we think of, generally capital-g “Great Men”, are hardly the only such individuals like that. They’re only the ones we can see. What of, for instance, the old Argive mother – her name lost to history – who killed Pyrrhus of Epirus, considered the greatest general of his generation, with a lucky throw of a roofing tile, both ending his career but also setting in motion a chain of events where the power vacuum left by Epirus would be filled by Carthage and Rome in a way that would bring those former allies (allied against Pyrrhus, in fact) into a shattering conflict which would then pave the way for Roman dominance in the Mediterranean? History must be full of innumerable such figures whose actions created and closed off courses of events in ways we can never know; how do we know that there wasn’t some would-have-been Temujin on the steppe in 100AD but who was killed in some minor dispute so very minor it leaves literally no evidence behind?

(The fancy way of putting the influence of all of those factors, both the big structural ones and the little, subject-to-chance ones, is to say “history is contingent” – that is, the outcomes are not inevitable but are subject to many forces large and small, many of which the lack of evidence render historically invisible.)

Bret Devereaux, “Fireside Friday: October 15, 2021”, A Collection of Unmitigated Pedantry, 2021-10-15.