[photo by Lois Payne]

I have been reading several fascinating books of late which, as often happens, seem to coalesce at a certain point into similar themes. What first got me thinking was Cathy Gere's Knossos and the Prophets of Modernism, where in her introduction she tells of Thomas Huxley's 1880 essay entitled "The Method of Zadig: Retrospective Prophecy as a Function of Science." The term 'prophecy' here is unfortunate, for the method introduced is not really prophecy, though it may appear to be so by those not privy to the method involved, which is simply creative use of reasoning to obtain seemingly unobtainable knowledge.

To justify his terminology, Huxley explains that while the 'foreteller' informs the listener about the future and the 'clairvoyant' informs the listener about events at a distance, the retrospective prophet bears witness to events in the deep past. What unites them all is 'the seeing of that which, to the natural sense of the seer, is invisible.' (7)

Zadig, the title character in Voltaire's novel of the same name, was a Babylonian philosopher who was able to give an extremely accurate description of a princess's lost dog, even though he had never seen the dog. Here is what he deciphered from dog tracks in the sand:

Long faint streaks upon the little elevations of sand between the footmarks convinced me that it was a she dog with pendent dugs, showing that she must have had puppies not many days since. Other scrapings of the sand, which always lay close to the marks of the forepaws, indicated that she had very long ears; and, as the imprint of one foot was always fainter than those of the other three, I judged that the lady dog of our august Queen was, if I may venture to say so, a little lame. (8)

Evidently, Zadig was too good at his trade, for he was said to have been executed for making it possible to potentially meddle with ancient sacred truths.

This same method was also used by Sherlock Holmes. Consider the classic example from Conan Doyle's “Sign of the Four,” where Watson tests Holmes' abilities by giving him a watch he has recently acquired from his brother.

I handed him over the watch with some slight feeling of amusement in my heart, for the test was, as I thought, an impossible one, and I intended it as a lesson against the somewhat dogmatic tone which he occasionally assumed.

Holmes, looks the watch over carefully, lamenting that it had been recently cleaned, which no doubt destroyed valuable evidence. But still, he says,

 

“I should judge that the watch belonged to your elder brother, who inherited it from your father… The W. suggests your own name. The date of the watch is nearly fifty years back and the initials are as old as the watch; so it was made for the last generation. Jewelry usually descends to the eldest son, and he is most likely to have the same name as the father. Your father has, if I remember right, been dead many years. It has, therefore, been in the hands of your eldest brother."

Watson admits that this is correct, and Holmes continues:

“He was a man of untidy habits—very untidy and careless. He was left with good prospects, but he threw away his chances, lived for some time in poverty with occasional short intervals of prosperity, and finally, taking to drink, he died. That is all I can gather.”

Watson is angry, thinking Holmes has been prying into his private life, but Holmes assures him that he deduced everything with a certain amount of probability.

“What seems strange to you is only so because you do not follow my train of thought or observe the small facts upon which large inferences may depend. For example, I began by stating that your brother was careless. When you observe the lower part of the watch-case you notice that is not only dented in two places, but it is cut and marked all over from the habit of keeping other hard objects, such as coins or keys, in the same pocket. Surely it is no great feat to assume that a man who treats a fifty-guinea watch so cavalierly must be a careless man. Neither is it a very far-fetched inference that a man who inherits one article of such value is pretty well provided for in other respects… It is very customary for pawnbrokers in England, when they take a watch, to scratch the number of the ticket with a pin-point upon the inside of the case. It is more handy than a label, as there is no risk of the number being lost or transposed. There are no less than four such numbers visible to my lens on the inside of this case. Inference—that your brother was often at low water. Secondary inference—that he had occasional bursts of prosperity, or he could not have redeemed the pledge. Finally, I ask you to look at the inner plate, which contains the keyhole. Look at the thousands of scratches all round the hole—marks where the key has slipped. What sober man’s key could have scored those grooves? But you will never see a drunkard’s watch without them. He winds it at night, and he leaves these traces of his unsteady hand. Where is the mystery in all this?

Note that not only is this exactly the type of reasoning Huxley refers to as retrospective prophecy, but it has the same effect upon people who don't understand the method. It only seems strange to those who do not follow the train of thought or observe the small facts upon which large inferences are made.

If we are not among the cognoscenti, our claim might be that not only are certain things not known, but that they are unknowable, and this is the aspect of retrospective prophecy that interests me here, for what is knowable and what is unknowable changes according to technological advances.

To say we are not among the ‘cognoscenti’ is not to say we are ignorant, for even those with high intelligence might not have the technological ability to see the small facts which allow for large deductions. The physicist Michio Kaku makes this clear in the epilogue of his book Physics of the Impossible.

Let me remind you of a speech given by Nobel laureate Albert A Michelson in 1894 at the dedication of the Ryerson Physical Lab at the University of Chicago, in which he declared that it was impossible to discover any new physics: “The more important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote…” … His remarks were uttered on the eve of some of the greatest upheavals in scientific history, the quantum revolution of 1900, and the relativity revolution of 1905. The point is that things that are impossible today violate the known laws of physics, but the laws of physics, as we know them, can change. (285)

Kaku also tells of the famous French positivist philosopher Auguste Compte, who claimed, in 1825, that it would always be impossible for science to determine what stars were made of—they’re just too far away! And yet a few years later the science of spectroscopy allowed scientists to analyze light from the stars and thus determine their chemical makeup. Even today such claims are made with seeming authority, as, for example, by the astronomer John Barrow: "All the great questions about the nature of the Universe—from its beginning to its end—turn out to be unanswerable." (287)

The statement makes sense—the space-time boundaries of the universe seem as distant as the light from a distant star. But what new discoveries, I wonder, are in the works that will one day make him eat those words? I am continually amazed at the ingenuity that allows for the discovery of truths that were once thought unobtainable. Here are a few examples from Jared Diamond’s book Collapse: How Societies Choose to Fail or Succeed.

There is the puzzle of the Anasazi, who lived in the Chaco Canyon area of Northwestern New Mexico for more than five hundred years, from about A.D. 600 to around 1150, and then disappeared. Those who came after them, reoccupying their impressive pueblo dwellings, gave them their name, which simply means “ancient ones.” It was long thought impossible to determine when and for how long these people lived in their dwellings and why they ultimately left, but there are several particularly telling techniques that shed a great deal of light on these questions.

First, consider the tree ring dating method, known as dendrochronology. Every school child knows a tree’s rings indicates how old it is. This only becomes useful to archaeologists, though, if certain conditions prevail. For instance, in tropical rain forests tree growth is almost always constant, which makes it difficult to date very far into the past. Add to this that trees tend to rot rather quickly in the tropics. But in the arid Southwest, not only is the environment conducive to tree preservation, but the variance in rainfall from year to year means the trees grow with rings that vary from year to year: wider during a wet season, narrower during a dry. These rings not only show the type of weather during the tree’s growth, but also make for distinctive ring patterns when taken as a group, which allows for dating trees back thousands of years ago.

Thus, using recent trees whose dates are well known (since we know precisely when they were cut), we find a distinctive ring pattern in the latter growth years of a tree that is, say, 200 years old. We then look for this same pattern in (preferably) the early growth period of an older tree (of which we don’t know the cut date). When a match is found this older tree pushes back our chronology and we then look for a pattern in this tree and compare it to yet older trees, slowly pushing back our knowledge of the precise dates and weather patterns of the area. This is truly reminiscent of retrospective prophecy!

For a second retrospective methodology, consider pack rat middens. Diamond gives us the background:

In 1849, hungry gold miners crossing the Nevada desert noticed some glistening balls of a candy-like substance on a cliff, licked or ate the balls, and discovered them to be sweet tasting, but then they developed nausea. Eventually it was realized that the balls were hardened deposits made by small rodents, called packrats, that protect themselves by building nests of sticks, plant fragments, and mammal dung gathered in the vicinity, plus food remains, discarded bones, and their own feces. Not being toilet trained, the rats urinate in their nests, and sugar and other substances crystallize from their urine as it dries out, cementing the midden to a brick-like consistency. In effect, the hungry gold miners were eating dried rat urine laced with rat feces and rat garbage. (145)

The beauty of the packrat midden is twofold. Packrats never stray far from their nests in order to minimize both energy expenditure and the risk of predation by other more aggressive species. Also, as their name implies, they collect an assortment of vegetation within their nests, not to mention their feces (which allows us to determine their diet) and anything else they find of interest. In protective areas such as caves and overhangs packrat middens can last up to 40,000 years.

By identifying the remains of the dozens of urine-encrusted plant species in a midden, paleobotanists can reconstruct a snapshot of the vegetation growing near the midden at the time that the rats were accumulating it, while zoologists can reconstruct something of the fauna from the insect and vertebrate remains. In effect, a packrat midden is a paleontologist’s dream: a time capsule preserving a sample of the local vegetation, gathered within a few dozen yards of the spot within a period of a few decades, at a date fixed by radiocarbon-dating the midden.(146)

One of the fascinating pieces of information that emerges from this is that the now treeless desert in the Chaco Canyon was at one time a verdant pine forest. It can also be seen when this forest disappeared. Other methods of analysis (strontium isotope ratios) indicate exactly where the Anasazi went to get logs for their roofs once they had deforested their own area.

The most important aspect of these different methodologies is that they verify each other. Carbon dating can be calibrated by dendrochronology, which can then calculate dates on middens which can determine the flora and fauna of the area, which can be seen to coordinate with the weather during that specific time.

Without this kind of independent corroboration we are left with what Gould referred to as “just so stories,” ad hoc mythic stories purporting to explain various aspects of the universe. Astrology is a prime example of a just so story, a foretelling rather than a retrospection, but the principle is the same. Another strangely interesting example was pointed out recently in the blog Morbid Anatomy, which referenced an article on the lost art of mole mapping, that is, reading moles on the human body like a zodiac chart!

Astrology, phrenology, moles, core sampling, strontium isotopes, pollen and tree ring analysis, tachyons and neutrinos. All these are tiny pieces of evidence that are used to paint large deductions, yet some are stand alone narratives while others have multiple ties to other methodologies that in turn help to weave a circle of justification. It is these latter we should rely upon, for the more connections involved among disparate disciplines, the more assurance we have that we are not merely spinning cobwebs of our own substance.

Arthur C. Clark famously claimed that any sufficiently advanced technology is indistinguishable from magic. We have seen this to be true. Our job, as rational human beings, is to understand the difference.