Branching Time, Branching Histories

Friday 21 June 2024

Nick Nielsen
10 min readJun 24, 2024

Here we are at midsummer, and now the days must begin to get shorter. This is a sad reflection in the midst of summer, perfectly complementary to the happy reflection at midwinter when we know that the days must begin to lengthen, but this is an appropriate time for a meditation upon the fleeting sources of history. In the past several newsletters I have discussed history as a source of social cohesion, and I have widened the perspective of history to include both shared pasts and shared futures. But history (even in the wider sense that includes both past and future) is a problematic source of social cohesion, since a continuous tradition that relates the past to the future is rather the consequence of social cohesion than its cause. This is a chicken-and-egg problem. If a tradition manages to maintain itself over historical time, then it can become a source of continuity and cohesion, but from where does the continuity and cohesion derive that makes it possible for a tradition to establish itself over historical time?

At least as often as being a source of cohesion, history is a source of division. History is punctuated with periods of frenzied violence in which monuments of the past are systematically destroyed, with the assurance that this will allow us to build back a better future when we are freed from the burden of the past (of which Marx said, “The tradition of all dead generations weighs like a nightmare on the brains of the living”). On the other hand, there are also periods of brutal repression when future generations are sacrificed to maintain a past that seems to be threatened by novel visions of the future. Ideally we would be able to avoid both of these extremes, but both have been realized so frequently that it is naïve to believe that we have yet outgrown the swings of the pendulum.

History, then, is a dialectic of cohesion and division — or, if prefer a Biblical turn of phrase, binding and loosing — in which our shared past is riddled with differences that we can overlook or focus upon as the occasion presents itself. This has not gone unnoticed by historians. At the end of Collingwood’s “The Philosophy of History” of 1930 he wrote:

“All history is… an interim report on the progress made in the study of its subject down to the present; and hence all history is at the same time the history of history… This does not reduce history to something arbitrary or capricious. It remains genuine knowledge. How can this be, if my thoughts about Julius Caesar differ from Mommsen’s? Must not one of us be wrong? No, because the object differs. My historical thought is about my own past, not about Mommsen’s past. Mommsen and I share in a great many things, and in many respects we share in a common past; but in so far as we are different people and representatives of different cultures and different generations we have behind us different pasts, and everything in his past has to undergo a slight alteration before it can enter into mine. Quite apart, then, from any error in his or my interpretation of the evidence, our views of Julius Caesar must differ, slightly perhaps, but perceptibly. This difference is not arbitrary, for I can see — or ought to be able to see — that in his place, apart (once more) from all question of error, I should have come to his conclusions.”

Collingwood is here describing an indefinitely branching structure of history in which his historical past is different from Mommsen’s historical past, and, presumably, my historical past is different from Collingwood’s historical past. Everyone, it seems, has their own history; the advent of a new agent in the world is the point of origin of a novel history. We share a great many things, Collingwood assures us, but the overall structure of history is that of an indefinitely growing and branching structure producing new histories as rapidly as new minds are born into the world. There is no end to this process that is not arbitrarily imposed from without.

Theodor Mommsen was invoked by other historians as a symbol of erudition.

Collingwood’s philosophy of history was constructed around the idea of re-enacting the past thoughts of historical agents, so the problem that Collingwood highlights in this passage is crucial for his conception of history, but not necessarily for other conceptions of history. Beyond the details of Collingwood’s conception of history, his use of Mommsen is significant. Mommsen has been invoked by historians as a symbol of erudition. Giovanni Gentile, like Collingwood, employed Mommsen in this way in his Sistema di logica come teoria del conoscere (1917–1922), which has not yet been translated into English:

“Mommsen will say that he knows more about the most ancient history of Rome than Livy, and he will be telling the truth. But why? He thought more: he, the human spirit, which is not only Theodore Mommsen, but that spirit which in nineteen centuries matures its historical categories, its penetration of documentary material, always seeks, and thinks, always dissatisfied, and reflects, and finally writes the History of Rome as an act of a thought that makes all the previous ones obsolete, and by making them so gives them a value, which would be null if all interest in the history of Roman civilization and Mommsen had suddenly disappeared, and, for example, he had spent his life as an entomologist.”

I gather from the context that Mommsen must have said somewhere that he knew more Roman history than Livy, or maybe someone said this about Mommsen. I’ve been looking for the source of this but haven’t yet been able to find it. In any case, both Collingwood and Gentile are making a similar point: Mommsen knew more Roman history than Livy, and Collingwood knows more Roman history than Mommsen. Collingwood doesn’t actually say that he knows more than Mommsen, but that what they know is different, and he gives us a mechanism for this difference: each individual is distinctively embedded in history, and from this follows a slightly different perspective in each case. But, as Gentile observers, the later individual in history is the beneficiary of all previous thought about history, and by this mechanism Mommsen, later than Livy, knows more, and Collingwood, later than Mommsen, knows more.

Who knew more about Roman history, Livy or Mommsen? Mommsen or Collingwood?

Collingwood carefully observes that he and Mommsen share many things, but the difference is there nevertheless, and, while slight, the difference is still perceptible. This is generally true, and again it furnishes us with a mechanism: any two perspectives on history share knowledge to a greater or lesser degree, with the difference being more or less easily perceptible. What this doesn’t tell us is the threshold of difference at which these perspectives of history begin to generate conflicts, or the threshold beyond which the past is no longer a shared past, but is incommensurable. Mommsen shared much with Livy, but they were separated by two thousand years; Mommsen probably shared much more with Collingwood, whose life overlapped with his. Separation in time matters, but the continuous thread of Western civilization connects Livy, Mommsen, and Collingwood. A different kind of gulf separates these three from a historian from a different tradition.

How close do two perspectives on history need to be in order for two (or more) individuals to have a shared past? Depending on the context, a significant degree of difference may be consistent with a shared past, so that two or more individuals may possess a shared past for all practical purposes, and it is only when some particular issue arises that the difference between them is perceptible. On a microscale, I may disagree with my siblings about some recollection or interpretation of our shared childhoods, but in the big picture our views of this shared past are quite close, and any differences between them will be irrelevant for most purposes. On a macroscale, those who hold in common a shared tradition — like Livy, Mommsen, and Collingwood all being part of Western civilization — will recognize this tradition and their common belonging, and their disagreements could be reduced to imperceptible and therefore irrelevant details that will not matter for most practical purposes.

Borderlands, be they geographical or epistemic, bring out divided loyalties.

What I am spelling out here are what in newsletter 291 I called epistemic enclaves. The point I am making here is that epistemic enclaves have a core of agreement for all practical purposes, but there is also a large gray area in which epistemic enclaves overlap, and it would be easy to cite any number of particular situations in which those in the gray area see themselves as having more in common with others in the gray area than they have in common with those in the traditions to which they putatively belong. The obvious example here is that two individuals may be citizens of different nation-states but live in a common borderland, and they may feel more affinity for others in the borderland than they feel for those in the center of their respective nation-states. Or not. There are many examples from history in which individuals in borderlands have immediately set to killing their neighbors when their respective nation-states have been in conflict. Loyalties can be complex, and they can be divided.

Where there is a common core identity with a shared epistemic framework that works for all practical purposes, what this means for individuals is that their individual concerns that differ in some degree from the shared epistemic framework are like rounding errors: in most cases they can be ignored, but there may be contexts in which they suddenly, and perhaps also inexplicably, come to prominence. There is a spatiotemporal analogy to this with relativity. When any body is accelerated, it establishes its own temporality that differs from unaccelerated bodies with which it was formerly associated. In most terrestrial cases, not only would we not notice this, but it would require scientific instruments of extraordinary precision to detect time dilation for one body accelerated on a human scale. We could think of time not as a single linear arrow, but as an infinitely branching structure in which any acceleration initiates a new spatiotemporal milieux. On Earth, the acceleration in question is not enough to make a difference. These relativisitic effects are too microscopic to notice, much less to make a difference in practical terms. Some years ago two synchronized atomic clocks were flown in different directions, one in the direction of Earth’s rotation and the other in the opposite direction (the Hafele-Keating experiment in 1971), and it was demonstrated that the accelerated clock had experienced time dilation. Needless to say, the time dilation effect was so small that it was only detectable by atomic clocks, and made no difference in human time keeping.

The Hafele-Keating experiment flew atomic clocks on commercial flights to demonsrate time dilation.

Time on Earth is not free from relativistic effects, but the scale of movement on Earth is too small for these relativistic effects to have any bearing on human history. Thus on Earth we have a shared temporal framework in which the infinitely branching structure of time is effectively irrelevant and becomes a rounding error so small that most calculations will never take it into account. However, on cosmological scales, relativistic effects start to matter, and if we ever possess the technology to move at relativistic speeds, then human history will start to be affected by the infinitely branching temporalities of history that is unevenly accelerated. At first, this will only show up as a gray area in which the differences will not matter all that much — differences of a few days, weeks, months, or years. Allowed to continue, however, the differences would accumulate, and then new spatiotemporal centers would be increasingly alienated terrestrial temporality, until they defined their own history separate from Earth. This was the point of my recent essay “The Coming Coeval Age.” At present we are a long way from realizing this in its most radical form (using relativistic spacecraft to reach other planetary systems), but we aren’t far at all from separate off-world settlements that go their own way and are increasingly alienated from terrestrial norms.

The compounding of (relatively) isolated epistemic enclaves on Earth with the possibilities of relativistic spatiotemporal enclaves, which will also become epistemic enclaves in turn, will raise the complexity of human history beyond its current incalculable threshold. As we have seen, there can be a blurring and a rounding that makes it possible for communal life to continue despite differences in detail, and we can even imagine a blurring and a rounding on a greater scale that allows some kind of shared epistemic framework on a cosmological scale, but this would take us so far from the concrete realities of human life that it is questionable whether this could ever be meaningful or relevant. One can imagine the Encyclopedia Galactica as an epistemic framework on a cosmological scale, but we can also recall Carl Sagan’s human, all-to-human (or even Cold War, all-too-Cold war) presentation of the Encyclopedia Galactica.