Marvellous “Properties” 2: Philosophy

Now that we have concluded our reading of Ibn al-Jazzār’s Risāla fī’l-khawāss, the Epistle on Special Properties, let us see how it touches on some fundamental questions on the value of experience and experiment vis-à-vis theoretical knowledge.

The Risāla is a small work that alternates between a few theoretical paragraphs and an abundance of “examples” to justify its scientific thesis. The thesis, grosso modo, is that one should not rely on theory alone and much less on hearsay alone when considering the extraordinary natural properties and effects of some substances. Following every iteration of this line of argument, Ibn al-Jazzār provides us with a wealth of examples to make his point, citing an impressive roster of traditional authorities. Here is a sample,

According to al-Tabarī, when the tongue of a hoopoe is hung above someone who is forgetful, he will recover his memories. // They say that when you take a fang from the upper left jaw of a crocodile, and hang it above someone afflicted by fever, his fever will go away.

Help yourself to materia medica!

Naturally, during our reading we had many occasions for good cheer with the sometimes outrageous and often bewildering examples, commenting on how we should make sure to acquire this or that particularly helpful substance, like body parts of tortoises or lions. But beyond the banter, two points are worth reflecting on: 1) the vanity of rational understanding in the face of the marvellous, and 2) the unquestionable value of experience when reported from trustworthy authorities.

Ibn al-Jazzār goes almost as far as ridiculing the attempt at rationalising the wondrous properties of nature, making a perennially valid epistemological point: how can you claim that something is impossible or absurd, and not simply a reflection of shortcomings in your perception and understanding? This attitude is precisely the acknowledgement of and openness to “anomalies” that, in Kuhn’s language, may give way to needed new paradigms.

The second point follows: you have to stubbornly trust your own experience of the phenomena or, if not your very own (and here comes the twist), the experience of fully trustworthy authorities. That is, the chain of authorities is not hearsay and not mere bibliography, it is as if we ourselves had seen the fever abate under the crocodile's fang, and memories return under the hoopoe’s tongue. I may not have been there and made these experiences with crazy substances, but I trust Aristotle, and Galen, and Apollonius etc.

As ever, we find here how directly our very modern and cutting-edge questions are in conversation with medieval authors, and how from subjects like magic, alchemy and all that “crass baseless superstition” we are questioned, and indeed assayed and improved in our theory and our practice. Ergo, if you have some Arabic, don’t hesitate and join our weekly reading group, restarting in September. [J. Acevedo]

Heavenly Bodies and Their Accidents

As we continue our weekly readings of Sulayman al-Mahri’s Mir’at al-salak (Mirror of Travellers; see our previous post), wondering about the relation between cosmography and geography and navigation, as in one of the recent RUTTER Blog posts, we have come across an interesting live example of “saving the phenomena”, straight from the 16th-century Arabian Peninsula.

The context is Ptolemaic through-and-through, with al-Mahrī explaining in Chapter 5 what relates to the “accidents” of the planets in their courses. He takes a while to describe the mechanics of planetary movement, dwelling on the details of retrogradation which were so fundamental to the whole Ptolemaic edifice. So we need to brush up conscientiously on our pre-modern astronomy terms in Arabic, the epicycles, deferents, with their apogees and perigees, to follow carefully the exposition. But then, after a thorough explanation, we come across the following,

Now, it is obvious that the heavenly bodies bring to completion the circular movement inside their orb without experiencing any alteration that touches on the orb. For their movement is neither faster nor slower, nor do they go backwards on their path, or halt their movement in the actual fact itself (nafs al-amr). But all this has to do with the relation between our vision (hasab ru’yatinā) and the composition of the movements (tarkīb al-harakāt).

While it has become commonplace to cite Aristotle on the matter of “saving the phenomena”, it is well known that from the earliest times of Greek philosophy there was a tension between the perfect motion of the spheres—cf. Timaeus, “time is the moving image of eternity”—and the perceived irregularity of the astronomical phenomena. Most notable and seminal are the Platonic passages in Timaeus, Epinomis and the Laws, but for example, and more directly astronomical, here is Geminus of Rhodes (1st century BC),

The Pythagoreans, who were the first to apply themselves to investigations of this kind, assumed the movements of the Sun, the Moon and the five planets to be circular and uniform. They would not admit, with reference to things divine and eternal, any disorder such as would make them move at one time more swiftly, at one time more slowly, and at another time stand still.

Ptolemy (Almagest III, 1 and XIII, 2) is very clear about preserving as much as possible the simplicity of the models (Gr. hypotheseis), and the Middle Ages saw countless back and forth arguments on this matter, which might be said to be a conversation, at times heated!, between cosmology and cosmography, what we know to be de iure, and what we perceive to be de facto. It is all a series of disputationes maybe, lively and truly philosophical. How remarkable, then, that an unassuming Yemeni pilot of the 16th century, man of praxis and adventure, should join the conversation, echoing in his clear, matter-of-fact discourse, the arguments of so many centuries before him—from Pythagoras to al-Mahrī, just a blink of a scientific eye! [JA]

Cosmic Navigation and Cosmic Pilots

As we embark on a new academic year with our Arabic reading group, we start more in earnest to tackle the pages of Sulayman al-Mahri’s Mir’at al-salak li-kurat al-aflak (Mirror of Travellers into the Heavenly Spheres), a primer of astronomy for the education of maritime pilots in the early 15th century. Not so much of a primer really, but more like an intermediate-level handbook of cosmography.

The first pages tell us about the order of the heavenly orbs, how the universe is conceived as… an onion (that’s my image, not al-Mahri’s!), or more elegantly, as a compound of concentric spheres, within each of which move the planets or other heavenly bodies. It all starts from the centre of the earth, with the description of the elemental spheres wrapped around it: water, air, fire. This cosmology is of course in all its basics an Aristotelian cosmology, found in numerous accounts over most of ancient and medieval Eurasia. Latin versions abound, including some beautifully illustrated.

Gautier de Metz, 13th century.

Approximately at the same time that al-Mahri was writing his works, Iberian nautical science was being revolutionised by the incorporation of astronomical precision techniques to the extensive tried and tested savoir-faire of the pilots. Long-distance oceanic navigation elicited, or rather forced, technoscientific developments which brought its practitioners to new levels of skill. And yet, East or West, either in Atlantic or Indian Ocean waters, there is the lingering question: Did they really need to know about the system of the cosmos in order to take a ship from A to B? And if they did not need to know those cosmic subtleties, why did they keep learning them? Why would such a practical pilot as al-Mahri, who wrote excruciatingly detailed route descriptions, care to elaborate so much on what was practically philosophical knowledge? Was it just didactic inertia, a superstitious repetition of old doctrines?

The answer is most likely “No, they did not need to know,” just as a mechanic fixing a carburetor does not need to know the laws of physics, or a butcher the details of embryology. A more interesting question may be asked, though, especially in our times, when all the cosmology and astronomy of the nautical sciences has been encapsulated in little devices which use satellite geo-positioning technology, like GPS. The question, and we are only left to ponder, is How did that knowledge impact their navigation? Did it have any practical influence, or was it just a matter of “depth”, of ”taste” (sapere, saber, dhawq) added to the mental framework of the pilots? Next time you meet a 15th-century pilot, we know what to ask him! [JA]

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 bodhisattva Kuan Yin, armed against ignorance (Wellcome Collection).

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]