How many Charlemagnes are there?

The View from Oregon — 353: Friday 08 August 2025

Simon Conway Morris is known for arguing that, if there is other intelligent life in the universe, it would be a lot like us. Morris calls this “convergence” in Life’s Solution: Inevitable Humans in a Lonely Universe, and thinks this convergence is rare. We could, by analogy with Ward and Brownlee’s Rare Earth Hypothsis call this the Rare Humanoid Hypothesis. I’m going to call this biological convergence. A peer species elsewhere in the universe would not just look like us, it would be like us in certain ways that are significant in the scheme of things — it would originate and develop as part of a natural process (though Morris is a theist, so his version might call for divine intervention), and it would in the fullness of time come to an understanding of itself and its place in the universe much as we have.

This peer species would have a mind like ours, enabling it to think like us (intelligence convergence), and to do science like us (epistemic convergence). With science like ours, this human peer would be able to build technologies like us (technological convergence). Another species of this kind, with a peer science and technology, is implicitly what we have in mind when we engage in SETI searches. In my paper on emergent complexity pluralism (“Peer Complexity in Big History”) I tried to emphasize this, namely, that finding another intelligent being using technology like ours to communicate by radio or lasers implicitly involves a sequence of convergences, and that these convergences represent thresholds of emergent complexity that could also branch out as divergencies.

As unlikely as this sequence of convergences is, we can push it even further. In fact, I think we can push it to the breaking point. Beyond the convergence of biology, intelligence, science, and technology, we can imagine historical convergence. Suppose that we receive a clear and distinct SETI signal of detailed encoded information. When we decipher the message, we find that it tells us the history of some peer species, not only like us empirically and spiritually, but also like us historically. That is to say, imagine that this SETI transmission reveals to us a peer species with a peer history. And, beyond that, suppose that every peer species like us in this way also shares this peer history, so that every intelligent being like us also has a history like us. This is cyclical history on a cosmological scale, and even one repetition of our history would probably be about the creepiest SETI message that we could receive. However, we shouldn’t think of some other species as having a history parallel to ours, since the SETI transmission we receive presumably would have been traveling through the universe for hundreds or thousands of years, and would come from a species significantly further along in its history than we are, so it would be us repeating their history, not vice versa.

Just as some philosophers of history can make cyclical history sound reasonable, we could make cosmological-scale cyclical history sound reasonable. Given a peer species like us in so many ways, and given a sufficiently abstract view of history, we can easily imagine a roughly parallel history. Indeed, we’re already there if we pull back to reveal only the evolutionary development of the species and its capacities, because we’ve already set out with this as our scenario — the parallel history at this macroscopic scale of historical magnification follows ex hypothesi, as they say. But I said above that we can push historical convergence to the breaking point, and we do this by closing in on more detail. The more detail we delve into, the more unlikely it seems that there could be parallel histories of ourselves and some peer species.

It would take very little magnification to arrive at the level of history at which geography is relevant, and here a parallel history would require a planet with the same dispositions of land masses and oceans as ours, and this would (or should) test our credulity. Supposing another planet to have the same geography as ours is a bridge tool far, but even here we can equivocate. We could divide planets among some rough taxonomic categories, with waterworlds, worlds with a single continent, and worlds with a plurality of continents separated by oceans, and worlds without any oceans at all. Further, we could argue that a peer species could only arise on world roughly like ours, so the geography isn’t the same, but it’s close enough, and it provides a close enough historical experience to call their history and our history the same. But we can just keep upping the stakes until we eventually break the model of cosmological cyclical history.

If we assume that first contact is an important event in the history of a peer species, then we would have to posit that the SETI message communicating cosmological-scale cyclical history would involve the transmitting intelligence recounting their own first contact by way of a SETI transmission, also relaying to them the message of cosmological-scale cyclical history, and having a similar impact on their civilization. This is another way to break the model, since there would be a earliest temporal bound in the history of the universe at which a civilization could arise, and this first civilization would (again, ex hypothesi) not be able to receive a SETI transmission with this content, since they would be the first to experience this history. At this point, if we wanted to try to retain the scenario, we’d have to resort to an explanation that would be even stranger than cosmological-scale cyclical history.

For example, if we consider an indefinite future, this no hard future temporal bound to civilization, we could posit that a future civilization passes through its history and then transmits its SETI message backward in time to an earlier civilization, and each civilization in turn would transmit its message of cosmological-scale cyclical history backward to its predecessor. As fantastic as this sounds, even this scenario fails because the earliest civilization wouldn’t pass its message along to anyone (although it could try to do so, without knowing whether or not it was successful), and there is a future temporal bound for civilizations like ours (the upper bound being the end of the Stelliferous Era), so there couldn’t be an infinite sequence of civilizations sending messages backward in time. More generally, we could conclude that any universe with a natural history, i.e., with any historical directionality, communication among civilizations with peer histories could not be replicated because conditions would change due to the directionality. However, in an eternal inflation cosmological model this might be made to work at the multiverse scale.

It is interesting to note that this scenario would be incompatible with the scenario that any civilization in possession of a sufficiently advanced science and technology would succumb to the non-human equivalent of anthropogenic existential risk (xenomorphogenic existential risk?). It would require an advanced technology over a long period of time to successfully transmit a SETI message, so that if every peer civilization has the same history, more or less, then they would all have a history that allowed their science and technology to mature to the point that they could also successfully transmit a SETI message, implying that they don’t destroy themselves as soon as they acquire nuclear technology. Of course, a civilization could promptly destroy itself after having successfully transmitted its SETI message, and every other civilization could be likewise, so that this is at once both the culmination and the fulfillment of fate: “After this message, you will hear nothing more from us, as we are fated to destroy ourselves now that we have passed the baton in the cosmological relay of intelligence.”

But this scenario, viewed from different perspectives, cuts both ways for SETI. One possible solution to the Fermi paradox would be a fine-grained historical convergence on cosmological-scale cyclical history, and if we assume that a civilization had somehow discovered this, they wouldn’t want to transmit it because that would be revealing the fate of any civilization that receives the message, as the receiving party would then be able to watch their history unfold according to the account they have received from an earlier intelligence who had already been through it all. Presumably this would be objectionable — perhaps sufficiently objectionable that no transmitting civilization would dare to do so — thus providing an explanation for universal silence.

Looking back on the other convergences — biological, intellectual, scientific, technological, and whatever other thresholds you’d like to interpolate into the series — from the perspective of historical convergence, and its failure at some given degree of magnification, should this failure of historical convergence reflect on earlier converge in their sequence that could lead to the possibility of a peer history? If we can intuitively see that any fine-grained historical convergence must fail, else we would have a universe full of Caesars and Charlmagnes iterated wherever an intelligent species appeared, why is it not equally evident that any other fine-grained convergence — biological, intellectual, scientific, or technological — must also fail? Is it simply because history follows from and answers to different principles than the other sciences, marking off history as being essentially different from all other forms of emergence? But what then of the history of scientific and technological development that would lead to the capacity to transmit a SETI message of peer history? There is more to be said here, and I may return to his.