24 March 2023

Libraries of the East, Libraries of the West

Ten days of archival work in Cairo bring to my mind strongly the words of the great Palestinian poet Mahmoud Darwish, “The East is not quite just East, and the West is not quite just West” (lā al-sharqu sharqun tamāman wa-lā al-gharbu gharbun tamāman). In spite of our facile view of a compartmentalised world, and in spite of stark superficial differences, this insightful observation applies in many fields of human culture. The great libraries of the world, and in particular the great collections of manuscripts, confirm the poet’s intuition, insofar as they owe their very existence and appeal to materials from disparate origins and from a wide range of chronological origins.

It is beyond question that you will find more Italian manuscripts at the Vatican, and more Arabic manuscripts at Dar al-Kutub in Cairo, or French works in Paris, but what really characterises the great collections is that, like complex geological formations, they consist of layer upon layer of historical endowments. This is how, on one hand, they put things rightly in perspective, by showing how dynasties and temporal powers wane in the face of the timeless quest for knowledge, and on the other hand, by opening unexpected avenues of research and presenting the researcher with surprising choices, with prompts to re-think hypotheses, and in short, to do the living work of science, by mercurially adapting, and fine-tuning again and again the delicate balance between phenomena (what we find—or finds us!) and our theories (how we make sense of the findings).

Now, to add a dimension to Darwish’s sentence, and so to share it as it were from the horse’s mouth, I would suggest that the great manuscript collections also teach us that, “The Middle Ages are not quite just Middle Ages, and Modernity is not quite just Modernity.”

Clear periodisation becomes easier and convincing the more we distance ourselves from the manuscript sources. I mean, it is very easy to draw chronological boundaries and razor sharp periods when we are dealing with secondary literature, when we are comfortable in the coziness of the printed page, but when we face the centuries-old accrual of material from before the countries we know, from obscure origins in cities now extinct, and facing even more obscure transmission lines, we have to be chronologically humble, and to tread carefully, lets we are unfaithful to the evidence. In actual manuscript “reality”, there is an intertwining of ages, a beautiful and exhilarating sense of the interpenetration of historical periods which is partly what makes working with primary sources so inspiring, exciting, and challenging! [Juan Acevedo]

03 March 2023

A Planet-Less Nautical Astronomy

From the RUTTER crew conversations logbook, preserved for posterity: We have been wondering at the early modern pilots of the Indian Ocean, who famously used complex combinations of stars to navigate by night—a catalogue of about 150 celestial bodies was in their treatises— but, and here’s the question, without ever even bothering to mention the planets. By this I mean the five known at the time, Mercury, Venus, Mars, Jupiter and Saturn. The same planets without which Ptolemy’s astronomy would have been reduced to nothing, and the same planets without which astrology would have been unimaginable.

The reason for this absence is obvious, and it is a nice etymological lesson. A planet, as is well known, means in the original Greek a “wanderer”, a “vagabond”. Now, if you are going to depend on guidance through the night and through the vast expanse of the ocean, you cannot rely on something changeable. You need fixed, unchanging points of reference, and this is exactly what was provided by the night sky, those wanderers excepted.

How bright they are, and unflickering! We have just been witnessing in Lisbon the approach and conjunction of Venus and Jupiter, every day, in the sunset sky, very impressive. And yet for all their steady light, they are not good for navigation: one day they are here, next day there, one day going straight, next day retrograding… They are strong, but fickle. The importance that they have in the astrological view of the cosmos is quite indicative of the variable state of the world: matters of the world and we are not ruled by stars, which would make us constant, but by those wandering bright lights.

The lack of importance that the planets have in navigation is, in turn, quite indicative of the nature of this craft, and of how special is the state of being at sea and being in transit to a destination: there is peril, and there is the urgency to reach a place, and so all the variable concerns of the pilot are subordinate to accomplishing his task, as Ibn Mājid says, “going and returning with the passengers and the cargo safe.” [JA]

04 January 2023

Infirmities of Time

As a new Gregorian year sets in, and as we start a new year of Arabic readings, this week’s passage of Ibn Mājid’s Fawā’id could not be more appropriate for a good reflection on the passing of time.

In one of his trademark digressions from the hard technical details of his craft, Ibn Mājid launches into a lengthy poem lamenting the swift passage of time, speaking of lovers in the night, turtledoves, wine and stringed instruments—all the usual imagery of medieval Arabic love poetry—“pierced by dawn and by the muezzin’s voice as if by an arrow.” All this, remember, at the end of a lengthy chapter on sailing seasons, and on the calendrical accuracy and traditional knowledge needed to travel safely across the Indian Ocean. And then comes his reflection after the poem,

“It may be that the monsoon (sailing season) too is afflicted by time with some illness which our minds cannot begin to grasp. Because it is said that every year the season comes later by a quarter of a day of the sphere.”

This ingenious return from the romance of the previous verses to the chapter’s subject matter gives us concrete scientific indications and also a cosmological subtlety.

The scientific indication has to do with the specific solar calendar used by the Arab pilots at the time. It is known that it was a variation of the Yazdgerdi calendar, itself a development of the Zoroastrian calendar, but it is hard to pin down exactly which variant. Here it seems clear that it was a calendar of 365 days without any adjustment for the extra quarter of a day (the tropical year has roughly 365 days and a quarter), and this explains the fact that the seasonal dates were shifting, one day every four years—a known feature of some of the early Persian calendars.

The subtlety has to do with the Arabic word ‘illah, translated here as “illness” and often meaning also a “cause”. Suffice to say that the three semi-vowels central to Arabic writing are called hurūf al-‘ilal, “causal letters” or “letters of infirmity”, corresponding to the Hebrew “mothers of the reading” (imot qeri’ah/matres lectionis)—by being “weak”, like “accidents” of the consonantal fabric, they make articulation possible; they are the efficient causes of articulation.

In this particular case, the infirmity is the ever-uneasy discrepancy between solar days and the solar year (why, oh why can’t the sun return to the equinoctial point in an exact number of days!?). But through this “weakness” in the astronomical fabric, how many changes are set in motion, and how much science has developed!

Ibn Mājid’s point is a sort of poignant physico-lyrical subtlety: the order of the world is full of such little ”cracks”, “weak spots” which are as discreet doors to the forces of causality. They are happy accidents, hotspots for discovery, invention, but also turning points away from every stability, and so unhappy and sad from the point of view of the contented lovers.

As we start a new year, here is to many happy accidents of invention and discovery to our readers and colleagues. Kullu ‘am wa antum bi-khayr! [JA]

11 January 2022

Online Workshop: “Sailing the Early Modern Indian Ocean”

An international workshop to approach from various perspectives the generation, constitution and circulation of nautical-related knowledge throughout the Indian Ocean World, following the late medieval and early modern trade routes.
Join us on the 24 and 25 January to share “case studies”, problems, or curiosities in a collegial setting, benefitting from the expertise, insights and help of interested colleagues. And please spread the word among those who may be interested.
And here is the program, To register, please email juan.acevedo@fc.ul.pt

08 November 2021

Knowledge Weaponized

Towards the end of chapter 6 of his Fawā’id, after going over the complexities of various kinds of routes and course-plotting options, Ibn Mājid explains:

I have made distinctions (farraqtu), because the different skills (‘ulūm, “sciences”) are like weapons: sometimes you need a bow and sometimes a sword, sometimes a spear and sometimes an ax or a dagger, and yet, for all this, you may never be dispensed of using a knife.

The explicit point seems to be that every skill, as a subdiscipline of knowledge, has its own irreplaceable and particular application, and that it is necessary to have a rounded preparation, because, as he puts it later, borrowing a saying from Imam ‘Ali: “man is the enemy of anything he is ignorant of,” or rather, given the context, “man is at war with everything he is ignorant of” (al-insān ‘aduww mā jahilahu). That is (and we must put it in the context of piloting a ship through the ocean and having to land safely thousands of miles away), everything we ignore is a hostile prompt to catastrophic failure. And the obvious way to be prepared, or armed, is to acquire the panoply of knowledge required by our respective field.

The implicit point is in that initial “making distinctions”, associated to terms like farq, “distinction, discrimination, severance”, and furqān, an epithet of the Qur’an meaning “a criterion”. As it happens, this root-meaning of division and discernment is exactly the same of the English-Germanic skill, and also of Latin scientia. The suggestion that science and skill have a common origin in discernment/dissection should give us pause now, as it would be better developed in another post.

So now, instead, going back to the image of waging war against ignorance, we can see how the mighty ancient saying is so much better when applied in science than in politics: Divide et impera! or in Arabic, Farriq tasud!, discern and you shall rule. [JA]

30 July 2021

Arab Tridua: Three-Day “Weeks” in Arabia

This post is about a rather neglected aspect of time division in early Arabia. In his Fawā’id (IV, 7) Ibn Mājid explains: “Every month is divided in ten parts of three days each, and each part has its name.” Then he lists the ten triads or, more specifically, tridua: Ghurar, Nufal, Tusa‘, ‘Ushar, Buhr, Bīd, Durā‘, Muhāq, Hanādis, Ziyād, Surar. Most of the names are straightforward in meaning, relating to the appearance of the moon or to the date count, and the word “three” is implicit. For example, “The three of Tusa‘” (al-thalāth al-tusa‘) means something like “the three [days] of the ninth”, because this triad ends on the ninth day of the lunar month. Al-thalāth al-bīd means “the three of whiteness”, because they are near the full moon.

Keen-eyed readers will have noticed that the above list actually contains eleven tridua, not just ten. This means to reflect the garbled textual condition in which Ibn Mājid’s list reached his readers in the 15th century, with obvious ingrained misspellings and interpolations. The earlier references I can find for these names are Ibn Wādih al-Ya‘qūbī (9th century) and al-Bīrūnī (11th century), who give slightly different lists. In comparison to them, Ibn Mājid’s does look like the outcome of centuries of Chinese whispers.

Now, al-Bīrūnī explains first that the names are derived “from the distinctness revealed by the state and the curvature of the moon,” and shortly after that they are “taken from the faces of the moon and its curvature.” This is what I find warrants a thought on our concept of “week”. Our weeks derive in part from a division of the lunar cycle in quarters.

Let us leave aside for now the numerological relevance of the division in three, seven or ten, which we have discussed previously. We can see how the beautiful continuum of the lunation allows for as many divisions as our powers of observation allow us to determine distinct—hence nameable—units. How many nights do we need to appreciate each clearly distinct aspect of the moon?

Nama-rupa, in the Sanskrit philosophical terminology, “name-form”: mutually dependent and inseparable aspects of every phenomenon, everything that appears to then vanish “under the Sun.” The gentle and ever-so-fleeting light of the moon is perhaps the phenomenon par excellence, now there, now vanished… What is left to us, puny sublunary creatures is to wield our power to name, and thus, by naming, to create scientia, the knowability and the knowledge, a “possession for ever.” [JA]

06 July 2021

The Spacetime of Early Modern Navigation

As we continue to read chapter 4 of the Fawā’id, about the nautical rhumbs, and as we go through detailed descriptions of time and distance measurements, we come across technical concepts which in their practicalities bring us, once again, to reflect on some of the principles of our modern technoscience.

The distance unit in early modern Arab navigation was the zām (pl. azwām). The technical concept is the taraffā or tirfa, called by early Portuguese explorers the “Rule of the Leagues” (regimento das leguas), the function between the distance travelled, the latitude progress, and the azimuth of the destination: e.g. if you travel straight up north, it takes you one hour to shift your position by one degree northwards, but if you travel towards the north-east, it will take you longer to advance that same degree northwards. A nice image of this concept is given by the triangle below, where A is the point of origin, and the latitude difference between A and B would be one degree. Simply put: the AB diagonal path takes longer to reach the same parallel.

Now, how to measure the advance without any points of reference on the flat surface of the ocean? The key point is: time is a function of movement. Something has to move for there to be a sign of time, because, as ordinary language teaches us: “time passes”, and we speak about “a space” or “an extension” of time, and we ask “how long?” as if we were speaking of a stretch of a road or a piece of string.

The solution: look up from the surface of the ocean and into the sky, where the positions and the continuous movement of the heavenly bodies show us directions and show us time. This relation between movement and time brings to mind Plato’s formulation: “time is the moving image of eternity” (Timaeus 37d). A sundial illustrates this too, being somehow “a moving shadow of eternity”. The passing stars were the necessary reference, and so, one of the definitions of zām reads, “the distance it takes to raise the Pole Star by one eighth of a finger if the ship sails due north”.

Fundamental coexistence of space and time, and strikingly obvious continuity of their dimensions… What to make, in this light, of the complexities of the space-time formalism of contemporary physics, with their illustrious history and mathematical refinements? Is this yet another case of “nothing new under the sun”? The word itself, spacetime, goes perfectly well with the medieval perception of navigators—the consubstantiality of space and time was immediately obvious. Perhaps it is just a matter of continuing to deepen the dialogue, the centuries-old conversation between the depths of metaphysical speculation and the frontlines of physical enquiry. Time will tell. [JA]

01 June 2021

Ostriches? What Ostriches!?

The early Arabic sky has some ostriches running through it: one of the lunar stations of early Bedouin astronomy is called The Ostriches (al-Na‘ā’im), and two of the brightest stars in the sky, Fomalhaut (α PisA) and Hadar (β Centauri), are also called “ostriches”, zilmān. We have been reading about these ostriches for long months now and, busy with astronomical and nautical details, we missed the question obvious to any contemporary reader: what ostriches in Arabia?

It is a historically well-known fact that we humans, as cultural and mythical beings, always project on the night sky our lives, including both what surrounds us everyday and what informs our minds. This is how the Greeks had the Ship Argo and their deities and fabled animals above, while in Patagonia they had rheas in the sky, and in Australia emus. Of course, you could say that if the Greeks had a winged horse, the Arab bedouins could very well have had their ostriches and an ice cream cart too, but… is there something missing?

As it turns out—and this is the beauty of how uranography and astronomy intertwine with very down-to-earth disciplines across the natural sciences—there were ostriches in Asia Minor and Arabia, but they were hunted to extinction by the middle of the 20th century. The Arabian ostrich (Struthio camelus syriacus) was very close genetically to its North-African cousins, and it had an important place in the culture of the Middle East since prehistoric times, but alas, it could not survive the arrival of firearms and motor vehicles.

While they remain undisturbed in the night sky, though, they help us on several fronts. They bring to mind the frailty of life on this sublunar place, and they can make us wonder at how we relate to the configuration of the night sky: while we obviously project parts of our lives on those glittering lights, what do we receive from them? What is the quid pro quo we have with the stars? What does their “life” project on earth? As readers of this blog will remember, there are very early and strong arguments to say that every systematic, controlled, “mathematical” way of pursuing knowledge here below derives from the observation of those ostriches and their celestial companions. There seems to be, in a very strict etymological sense, a dialogue between the stars and men: logos going through between high and low and low and high, for the advancement of science. [JA]