Rational Reconstructions of Time
9 July 2016
Introduction to the Scientific Study of Time
If I had an educational institution in which I could dictate the curriculum, I would have as requirements for the first year at least these two courses: “How to read a scientific paper” and “Understanding scales of time.” Of the former I will only say that, in our scientific civilization, every citizen needs to be able to read a scientific paper, so as not to rely exclusively on popularizations from journalists (perhaps I will write more on this later). The latter — understanding scales of time — is what concerns me at present. When I survey my own attempts to come to an understanding of the differing scales of time employed by the different sciences, I am struck by the slowness of my progress, but also by the importance of making progress. An organized and systematic attempt to give a unified exposition of the historical sciences and the time scales each entails would, I think, contribute significantly to making the various special sciences mutually intelligible and to encourage rigorous interdisciplinary research.
Just to finish the thought of a curriculum appropriate for the population of a scientific civilization, I might also consider not only a first year course in scientific method — many schools have required courses in statistics, which is a good step in this direction — but also a course in the philosophy of science and scientific methods, in order to give a comprehensive sense of the scientific enterprise and to engage students in thinking critically about the nature and limits of scientific knowledge. A scientific civilization that knows its own limits is less likely to fall victim to its own hubris than one in which these limits are not clearly understood.
The Idea of a Rational Reconstruction
The human experience of time originates in what Husserl called inner time consciousness, and human time as immediately experienced never extends beyond the lifetime of a single individual. Time consciousness, then, is severely constrained by human limitations. Human consciousness, however, not only consists in time consciousness, but also is the source of human reason, and human reason has sought to surmount the fleeting experience of time consciousness by extending time beyond the limitations of individual consciousness and the individual lifespan. This I will call the rational reconstruction of time.
Any duration of time beyond that of the human lifespan must be rationally reconstructed because it cannot be experienced directly. Extremely brief durations of time, such as are often involved in particle physics, also cannot be experienced directly, because they occur at a rate (or at such a microscopic scale) that cannot be distinguished by human sensory or cognitive faculties. These extremely brief durations of time also must be rationally reconstructed.
What is rational reconstruction? I won’t try to give a straight-forward definition, but instead I will try to give a sense of how philosophers have employed the idea of rational reconstruction. The idea originally came to prominence in the early twentieth century among logical positivists. Here is a passage from Otto Neurath that has become a point of reference in the origin of the idea of rational reconstruction:
“There is no way of taking conclusively established pure protocol sentences as the starting point of the sciences. No tabula rasa exists. We are like sailors who must rebuild their ship on the open sea, never able to dismantle it in dry-dock and to reconstruct it there out of the best materials. Only the metaphysical elements can be allowed to vanish without trace.”
Otto Neurath, “Protocol sentences,” in Logical Positivism, edited by A.J. Ayer, Free Press, Glencoe, IL, 1959, pp. 199-208, there p. 201.
Neurath further developed his ship analogy in other essays:
“We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom. Where a beam is taken away a new one must at once be put there, and for this the rest of the ship is used as support. In this way, by using the old beams and driftwood the ship can be shaped entirely anew, but only by gradual reconstruction.”
Otto Neurath, “Anti-Spengler,” in Empiricism and Sociology, edited by Marie Neurath and Robert S. Cohen, Dordrecht and Boston: D. Reidel Publishing Company, 1973, p. 199
Here the emphasis falls upon the exigency of keeping the ship afloat, which is not the central concern of the rational reconstruction of time, but it would be an interesting exercise to apply this idea to the cognitive framework we all employ, with the necessity being active and effective agency in the world.
Quine adopted the analogy of rebuilding a ship at sea from Neurath. In his Word and Object, Quine quoted Neurath’s ship passage as an epigraph to the book and develops the theme of reconstruction throughout, extending Neurath’s positivist-inspired analogy more generally to philosophy, giving the idea contemporary currency in analytical philosophy.
Hans Reichenbach made the idea of rational reconstruction fully explicit:
“When we call logic analysis of thought the expression should be interpreted so as to leave no doubt that it is not actual thought which we pretend to analyze. It is rather a substitute for thinking processes, their rational reconstruction, which constitutes the basis of logical analysis. Once a result of thinking is obtained, we can reorder our thoughts in a cogent way, constructing a chain of thoughts between point of departure and point of arrival; it is this rational reconstruction of thinking that is controlled by logic, and whose analysis reveals those rules which we call logical laws.”
Hans Reichenbach, Elements of Symbolic Logic, New York: The Macmillan Company, 1948, p. 2
Reichenbach has a footnote to this passage saying that “rational reconstruction” was introduced by Carnap, and indeed Carnap has a typically technical exposition of rational reconstruction in his Pseudoproblems in Philosophy (a bit long to quote here). Carnap’s interest in rational reconstruction seems to be due to the great influence that Russell’s philosophy had on Carnap, and it would be an interesting investigation to compare Russell’s conception of logical construction (in the parsimonious sense that Russell uses this term) and Carnap’s conception of rational reconstruction.
Imre Lakatos made extensive use of the idea of rational reconstruction in a more comprehensive context than the more narrowly logical exposition of Reichenbach. Lakatos applied rational reconstruction to the history of science, which is essentially what I am suggesting here:
“The history of science is always richer than its rational reconstruction. But rational reconstruction or internal history is primary, external history only secondary, since the most important problems of external history are defined by internal history. External history either provides non-rational explanation of the speed, locality, selectiveness, etc. of historic events as interpreted in terms of internal history; or, when history differs from its rational reconstruction, it provides an empirical explanation of why it differs. But the rational aspect of scientific growth is fully accounted for by one’s logic of scientific discovery.”
Imre Lakatos, The Methodology of Scientific Research Programmes: Philosophical Papers Volume I, Cambridge, 1989, “History of science and its rational reconstructions,” p. 118
A generalization of the point Lakatos makes in this passage would not be limited to the history of science: we can say that history simpliciter is always richer than its rational reconstruction, but the important problems for external history are set by the rational reconstruction of history. And, I think, we will find this to be the case; rational reconstructions of time point us to the most important problems for the historical sciences.
Mythology: the First Rational Reconstruction of Time
Mythology is the first “big history.” By placing human lives and human actions in a mythological context, human beings are immediately and personally related to a cosmos of enormous scope, far beyond anything to be encountered in the lives of most individuals. In order to achieve this scope, experiences had to be pooled, and a composite, richer experience draw from an inventory wider and deeper than the experiences of any one individual. This is the essence of the rational reconstruction of time, which was later taken to much greater lengths in subsequent human development.
In retrospect, mythological cosmologies are ethnocentric and parochial, usually bound to the biome of a given biocentric civilization, but in their time they constituted the uttermost and outermost reach of human reason, projecting human concerns into the heavens and beneath the Earth. Mythological cosmologies were as comprehensive as they could be at the time, given the limitations of human knowledge under which mythologies took shape.
While mythology is a rational reconstruction of the human condition, we can also can see the rational reconstruction of mythology itself when philosophically-minded later readers of mythology attempted to further bring the mythological cosmos into line with the increasingly rational order of human civilization. Plato famously wanted to ban all poets from his ideal republic, because the stories that poets tell about the gods are not always edifying, and Plato’s republic aspired to exercising absolute control over mythic narrative, to the point of inculcating a “noble lie” intended to reconcile each segment of the population with its social position. That is to say, mythology was to be employed as a tool of social control, which has always been a danger for historical thought.
Classical History: the Second Rational Reconstruction of Time
The distinctive Greek gift for and contribution to rationality was expressed not only in philosophy and the earliest science, but also in works of art — the Parthenon is a monument to rationality, among other things — and literature. The Greeks invented the literary genre of history, and, once they invented history, disagreed on whether it was an art or a science. This was a perennial problem of classical historiography, but is no longer a burning question today, as the advent of scientific historiography has changed the terms of the debate in historiography.
It is at least arguable, however, that scientific historiography was always implicitly present from the origins of history in Herodotus and Thucydides, but no science existed in the time of the ancient Greeks that could realize this potential. The original Greek term used for the title of Herodotus’ The Histories — ἱστορία — means inquiries, i.e., Herodotus conceived his work as an inquiry in the past, and so was part and parcel of the Greek imperative of rationality. Indeed, rationalism applied to the apparent sequence of historical accidents that is the past might well be considered the non plus ultra of rationalism. However, the method of Herodotus’ inquiries was not scientific (in the Greek sense) or logical, but rather narrative.
The extent to which history in this classical sense (one might say, in the Herodotean sense) truly is a rational reconstruction, and not a mere recounting of facts, i.e., a chronicle, is revealed by Arthur Danto’s study of the logic of narrative sentences in his Narration and Knowledge (and which logic of narrative I previously mentioned in Our Intimacy with the Past). Even the most complete account of events as they happen cannot express how the meanings of earlier events are changed by later events, which provide the context and perspective for interpreting earlier events. While Danto did not say so, the mirror image of this insight applies to the future, so that the present is given meaning in relation to its expected outcome, and expected outcomes are valued on the basis of present experience (and unexpected outcomes are also judged in terms of their divergence from expectation). This would be a theme that Big History would begin to explore, although not in these terms.
What we traditionally call history (i.e., Herodotean history) is simply that fragment of the whole of the temporal continuum narratively reconstructed from human records. We can understand this by a sensory analogy: we know from study of the electromagnetic spectrum that human eyes are able to see only a small portion of the EM spectrum. Beyond the abilities of human eyes, pit vipers can sense the infrared beyond the red end of the visible EM spectrum, and insects can sense ultraviolet beyond the violet end of the visible EM spectrum. Beyond the capacity of naturally evolved eyes to sense EM radiation, we can employ technology to detect radio waves, x-rays, and the rest of the EM spectrum. What human beings have called history is like the small “visible” portion of the EM spectrum: it is the small portion of the temporal continuum “visible” to human beings. The narrative method of traditional historiography allows us to reconstruct just so much history in human terms and to make it understandable to us.
Scientific Historiography: the Third Rational Reconstruction of Time
Already in classical antiquity we can see the scientific spirit at work in Ptolemy’s Almagest. Ptolemy wrote as a scientist, and not, like Herodotus, as an historian. As his science is now archaic, it is read only for its historical interest today, but in Ptolemy we can glimpse, in embryo, as it were, the scientific method in its characteristic attempt to transcend human limitations and the constraints of the human condition. In the Almagest Ptolemy compares his observations with the best observations of earlier writers, especially Hipparchus, even noting the margin of error inherent in observations due to the construction and position of instruments (cf. especially Book Seven on the fixed stars). In his chapter on determining the length of the year (Book Three, I), Ptolemy is always trying to get the oldest observations to compare with his observations, noting that nearly 300 years had elapsed between Hipparchus’ observations and this own, and reaches further back into Egyptian sources for data 600 years prior.
There is a difference in degree, but not a difference in kind, between these observations of Ptolemy and Freeman Dyson’s discussion whether the laws of nature change over time in “Time without end: Physics and Biology in an Open Universe” (1979). Dyson discusses what has since come to be called the “Oklo Bound,” based on the radioactive byproducts of the naturally-occurring Oklo fission reactor in Gabon. Dyson wrote:
“The fact that the two binding energies remained in balance to an accuracy of two parts in 1011 over 2.109 yr indicates that the strength of nuclear and Coulomb forces cannot have varied by more than a few parts in 1018 per year. This is by far the most sensitive test that we have yet found of the constancy of the laws of physics. The fact that no evidence of change was found does not, of course, prove that the laws are strictly constant. In particular, it does not exclude the possibility of a variation in strength of gravitational forces with a time scale much shorter than 1018 yr. For the sake of simplicity, I assume that the laws are strictly constant. Any other assumption would be more complicated and would introduce additional arbitrary hypotheses.”
Dyson, like Ptolemy, was employing the best scientific measurements and observations of his time in the attempt to transcend his time, though while Ptolemy’s rudimentary methods spanned a few hundred years, science can now comprehend a few billion years. The transcendence of immediately experienced human time by scientific scales of time is the rational reconstruction of time made possible by the historical sciences, and, by extension, for scientific historiography.
While the spirit of science is as old as classical antiquity, and it emerged from the same Greek world that gave us Herodotus and the Greek historians following Herodotus, scientific historiography did not begin to come into its own until the nineteenth century. Besides Ptolemy there were a few other notable intimations of scientific historiography to come, as in Nicholas Steno’s laws of superposition in geology. The historical sciences began to realize their potential in the geology and biology of the nineteenth century in the geology of Lyell and the biology of Darwin. Within a few years’ of the appearance of Darwin’s Origin of Species, Lyell Published Geological Evidences of the Antiquity of Man, which reconceptualized humanity in the context of geological time. Later in the nineteenth century, scientific dating techniques such as varve chronology (varves are annual deposits left by melting glaciers) and dedrochronology (tracing overlapping tree rings backward in time) began to give exact dates for historical events long before human records. Scientific archaeology (as opposed to mere treasure hunting) began about the same time.
Scientific historiography reconstructs time employing the resources of the scientific method, which made the reconstruction of time systematic. As long as science continues to develop, and is not allowed to drift into stagnancy, scientific historiography can continue to add depth and detail to this historical record. Scientific historiography extended the narrative tradition of history beyond texts written by human beings to the text of nature itself; the whole of the world became the subject of historical inquiry in the form of the historical sciences, which reconstructed a narrative of Earth entire, and eventually also of the universe entire, which latter became the remit of Big History.
Big History: the Fourth Rational Reconstruction of Time
Big history takes a step beyond the initial scope of scientific historiography, not merely narrating human history on the basis of what science can tell us where texts are silent, but in going beyond human history to a history of the universe entire, in which human history is contextualized. As I write this the 3rd IBHA conference is about to take place next weekend in Amsterdam, and I am a bit disappointed that I won’t be going, as I enjoyed the 2nd IBHA conference I attended a couple of years ago (cf. Day 1, Day 2, and Day 3).
The approach of big history did not come out of nowhere, but was building since the discovery of “deep time” in Steno’s laws of superposition, but especially the geology of James Hutton, then Charles Lyell, and later yet geological time scales brought to the study of life by Darwin. Science that dealt in millions of years and then billions of years slowly acclimated informed human minds of the possibilities for science completely freed of anthropocentric constraints. A hundred years ago, in the early twentieth century, we began to glimpse the size and the age of the universe entire, extending scientific scales of time beyond the Earth and the inherent geocentric constraints of human thought.
How can a human being, starting from the human experience of time, ever come to understand the life and evolution of stars, galaxies, and the largest and oldest structures of the cosmos? This grandest of historical reconstructions is possible because the universe is large and old and diverse. We cannot witness the formation of our own sun or our own planet, but we can look out into the universe and see stars in the process or formation and planetary systems in the process of formation (i.e., protoplanetary disks). If we are sufficiently diligent in surveying the cosmos, we can put together an entire sequence of the evolution of stars and planetary systems, drawn from different individual instances all today at different stages of development. While processes of stellar formation and planetary system development take place on a scale of time that human beings can never directly perceive, our reconstruction of these processes can be made comprehensible to us in this way. And when we are able to travel among the stars and to study life on many different worlds, we will be able engage in the astrobiological equivalent to this cosmological seriation, and similarly so with civilization and other forms of emergent complexity.
Big history provides a comprehensive context in which all of these scientific seriations of time scales beyond human perception can be concatenated in a single grand reconstruction of the whole of time as it is accessible to contemporary science. And, on the basis of contemporary science, Big History represents the culmination and non plus ultra of scientific historiography. Beyond the limits of empirical evidence methods other than science must be employed.
Formal Historiography: the Fifth Rational Reconstruction of Time
The fifth rational reconstruction of time is a rational reconstruction that has not yet been constructed, but we can see, on the horizon, that this is the natural teleology of the development described above. As inductive empirical science matures and grows in sophistication, there is an increasing tendency both to rigor and to integration with other physical theories. Sometimes the imperative to greater rigor is not historically obvious, as an empirical science may remain static in terms of its formal development for a long time — sometimes for centuries. But the need for formal rigor is eventually felt, and some clever soul somewhere has an “A ha!” moment that shows the way to a formal surrogate for a previously intuitive approach. This will be true for historiography as well.
There is a contemporary school of thought — cliodynamics — attempting to transform history into an empirical, testable science, employing numerical methods and quantification. In the bigger picture, scientific historiography more generally speaking adopts the formal methods of the other empirical sciences, and this increases the rigor of historical thought over time, but these efforts remain within the paradigm of inductive empirical science. When history is eventually formalized, it will follow the trajectory of earlier empirical sciences. First the work of scientific historiography must come to maturity, and then we will be in a position to engage in a formal scrutiny of the assumptions made in scientific historiography. Some of these assumptions will be common to other empirical sciences (in the traditional Euclidean language, these will be common notions, or axioms, that are not specific to some particular subject matter) while other assumptions will be unique to scientific historiography and will thus constitute the differentia of historical thought (postulates in Euclid’s terminology).
Most working scientists in daily practice do not employ fully formalized reasoning because it is cumbersome and slow, and, in fact, inductive empirical science can continue in its traditional methodology almost untouched by formalization. There are axiomatizations of general relativity, for example (cf., e.g., “An Axiomatization of General Relativity,” Richard A. Mould, Proceedings of the American Philosophical Society, Vol. 103, No. 3, Jun. 15, 1959, pp. 485-529), but this is not the way that most physics is done today. One might think of formalization as the highest level of emergent complexity yet attained within cognitive astrobiology, with mythology, narrative history, scientific historiography, and Big History all as earlier emergents in a sequence of emergents with the later supervening upon the earlier. All of these forms of human thought about time will continue to develop — they will not be replaced or superseded by formal historiography — but it will be formal historiography that moves the discipline of history forward into the terra incognita of time.
With the existence of hard limits to the historical sciences as represented by prediction walls and retrodiction walls, on what material will formal historical proceed? Let me attempt to give a sense of the kind of formal reasoning that can extend formal historiography beyond the constraints of observation and empiricism.
It has become commonplace for physicists to assert that, since time began with the big bang, that it is nonsensical to ask what preceded the big bang. This is, we must honestly admit, a rather tortured piece of reasoning (not to mention circular). While it is true that the big bang constitutes a retrodiction wall beyond which contemporary science cannot pass, and so is a boundary to empirical science, it is not an absolute boundary to human reason. To assert that there is nothing beyond or before the big bang is a perfect demonstration of the fact that human reason does not stop at empirical prediction walls. While it is a perfectly intellectually respectable claim to assert that there was nothing before the big bang, it is not a scientific claim, it is a philosophical claim. And, by the same token, it is a perfectly respectable claim to assert that there is something beyond the observable universe, including something before the big bang, but that this is inaccessible to contemporary science. Again, this is not a scientific claim, but a philosophical claim. In this sense, both of these claims are on the level, as it were.
There is no conceivable form of scientific research that could verify the existence of nothingness prior to the big bang. Philosophically, I would assert that producing evidence of nothingness is ipso facto impossible, and hence ruled out a priori, hence ruling out any scientific claim of nothing preceding the big bang. (Either that, or “nothingness” means something very different for the physicist as compared to the philosopher. And this is most likely the case: the two are talking — if indeed they ever talk — at cross-purposes.) The recognition of a nothingness outside or before the retrodiction wall presented by the big bang can be further illuminated by thought experiments proposed by Sydney Shoemaker and W. H. Newton-Smith that demonstrate the possibility of empty time (I will not attempt to give a summary of these thought experiments here; the reader is urged to consult these authors directly; cf. Newton-Smith’s The Structure of Time, II, 4, pp. 19-24).
These are the materials with which a formal historiography will grapple, along with the concerns of what I have called infinitistic historiography and infinitistic cosmology. In this way, formal historiography will transcend even the grand reconstruction of the whole of time accessible to contemporary science that I mentioned above in connection with Big History.
While the accidents of history might seem to be the last place that anyone would look for fertile ground for the formalization of knowledge, history, I think, will surprise us in this respect. And the surprising applicability of formal methods to history will constitute yet another rational reconstruction of time.
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