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.
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]
