This remained an age of intellectual achievement and some of its major figures were able to break away from their native cities and achieve independent research of the highest order. Among the most significant is Claudius Ptolemy, who worked in Alexandria between 127 and 141. Ptolemy’s background is unknown. The name ‘Ptolemy, originally royal, of course, had become quite common among Greeks in Egypt by this time but ‘Claudius’ suggests Roman citizenship, possibly granted to his family by the emperor himself. Ptolemy was certainly born in Egypt but whether as a native of Alexandria or another Greek city is unknown. He was a polymath, known to have written on music, mathematics (proposing new geometrical theorems), and optics (the earliest treatise on refraction), although his greatest work was in astronomy and geography, in both of which he was a giant.
In astronomy Ptolemy had access to data from Babylon and he was much indebted to Hipparchus (see earlier, p. 350) but he added his own observations to take the subject to new peaks. He was eventually able to list 1,022 stars in 48 constellations. His findings were brought together in his Syntaxis, later known by the Arabs as the Almagest. The Syntaxis begins by listing the arguments for an earth-centred universe and then goes on to develop the earlier explanations of the movements of the planets. Although, like his predecessors, Ptolemy worked with a geocentric model of the universe, he went beyond this in positing another point, the equant, around which the circles which each planet followed revolved, and through this he was able to account for even more observed phenomena. The Almagest marked a radical break with what had gone before, not least because it broke up the apparent harmony of earlier observations. The work was, in the words of Geoffrey Lloyd, ‘extraordinary for the rigour of its mathematical arguments, for the range of ideas encompassed and the comprehensiveness of the results proposed.
In his Geography Ptolemy introduced minutes and seconds into degrees, insisted on the continual rechecking of observations, and tackled the perennial problem of how to represent the globe on a flat surface. Just as in astronomy Ptolemy relied on Hipparchus, in geography he drew heavily on the works of a near-contemporary, Marinus of Tyre, who plotted places according to regular lines of longitude and latitude and so deserves an accolade as the father of mathematical geography. Even while correcting Marinus, Ptolemy is happy to acknowledge Marinus’ achievement, but the subsequent adulation of Ptolemy in the Islamic world meant that Marinus’ texts and his maps (which were reputed to be the first to show China) were not recopied.
In fact, Ptolemy’s enormous status and his adoption by the medieval west, through translations from the Arabic, was not always healthy. His astronomy became frozen into the medieval curriculum and it was only when his hypothesis of an earth-centred universe was challenged by Copernicus and his geography by explorations in the sixteenth century that progress in these fields could be resumed. Ptolemy’s lasting influence in the world of the natural sciences came from defining astronomy through mathematical models—‘this must be counted as one of the most significant of all events in the entire history of Western science’ (John David North).
Galen (ad 129-C.200) was born in Pergamum and was given an extensive education in the major Greek philosophers by his ambitious father before he turned to medicine. (Among his earliest experiences as a doctor was the patching up of wounded gladiators.) After study in a number of Greek cities, including Alexandria, Galen sought his fortune in Rome, and spent most of the rest of his life there until his death. His education left him with an unbridled self-confidence in his intellectual abilities. He was polemical by nature and his extensive critiques of his rivals are often the only record we have of their now vanished works.
Galen was a prolific writer and self-publicist. The range of his medical work alone is staggering: something like 20,000 pages survive, covering every aspect of human health. There are extensive commentaries on his predecessors (though sadly all those on Aristotle are lost), and the main reason why Hippocrates was so highly regarded by later generations is that Galen showed immense respect for the works attributed to him. However, Galen ranged far more widely than this. He was truly one of the finest minds of the Second Sophistic. He was acutely aware that Hellenistic science owed its terms and approach to koine Greek and so he was determined to preserve koine as a means of expressing himself while also acknowledging Attic as a pure ‘elite’ language for anyone who wanted to assert status. His thoughts on this, his study of etymologies of words, and his search for precision in their use, make him an important figure in linguistics even if he was typically elitist. ‘Greek is the most pleasant language. . . and the most fitting for humans. If you observe the words used by other peoples in their language, you will see that some closely resemble the wailing of pigs, others the sound of frogs, others the call of the woodpecker.’ He was fascinated by the organization of knowledge. Recent work is emphasizing his importance as a logician. ‘Galen’, to quote Geoffrey Lloyd again, ‘is probably unique among practising physicians in any age or culture for his professionalism as a logician. . . conversely he is also remarkable among practising logicians for his ability in, and experience of, medical practice.’
Galen was the supreme exponent of dissection and loved showing off his skills. ‘His vivisections fused the intellectual competition of Second Sophistic performance with the violent manipulation of bodies characteristic of Roman spectacle’ (Maud Gleason). One could say that his public displays were a form of rhetoric. Even though, unlike his Alexandrian predecessors (see p. 530 above), he was forced to rely on animals for his experiments, he refuted the traditional view that the arteries hold air. He did not grasp the principle of circulation—he had the blood passing through invisible pores. Nevertheless, he was able to distinguish some of the functions of the liver, heart, and brain and to observe contractions of the stomach in digestion and the peristalsis of the alimentary canal. He carried out experiments on spinal cords to try and pinpoint the relationship between parts of the cord and specific motor functions of an animal. He certainly deserves the title of founding father of experimental physiology.
The discovery of a new text by Galen, Peri Alupesias, ‘On the Avoidance of Grief, in 2005 by a French student working in a monastery in Thessalonika, has brought us an account of a fire in Rome that will appall any bibliophile. It took place at the end of winter in 192 and swept across the Palatine Hill destroying the imperial libraries there as well as the library in the Temple of Peace in the Forum. Among the losses were many texts from Galen’s own library that he had deposited for safekeeping while he was out of Rome. He especially mourned the loss of medical recipes of which he had no copies but in the other libraries there were other important texts, including some of Aristotle and Theophrastus and the Stoic philosopher Chrysippus that may have been the only copies. As a comment, Galen also lets us know that the papyri in the library of Tiberius had already been made unreadable through the damp that has stuck them together. It is a vivid insight into the sheer abundance of libraries in Rome and the vulnerability of their codices and papyrus rolls to damp and fire.
Galen refused to be dogmatic about matters for which he could find no physical or logical evidence. ‘Whether the universe is uncreated or created, or whether there is something outside it or not, I say that I don’t know’ (from On My Own Opinions). It was impossible to discover the origins of the earth and the question was therefore not worth serious consideration. Yet Christians accepted that Galen had enough belief in a single creative force for his ideas to be reconciled with theirs and his works were incorporated into medieval medical practice (from a text of his collected works compiled about ad 500). However, his innovative experimental approach and his rigid application of logic was forgotten as he became the major authority whose works were followed slavishly. Again, as with Ptolemy, it was only during the Renaissance that renewed observations of the human body queried the accuracy of his findings and even then he remained influential among physicians into the nineteenth century. Then he was surpassed, his works overlooked, and it is only now that he is being recognized as one of the finest minds of antiquity. The vast quantity of his surviving works is slowly being translated and admiration for his achievement continues to grow. (See the essays in R. J. Hankinson (ed.), The Cambridge Companion to Galen, Cambridge, 2008, and C. Gill, T. Whitmarsh, and John Wilkins (eds.), Galen and the World of Knowledge: Greek Culture in the Roman World, Cambridge, 2009. The recent biography by Susan Mattern, The Prince of Medicine, Galen in the Roman Empire, Oxford and New York, 2013, has received excellent reviews.)
The equilibrium between Rome and the provinces, between the emperor and the senate and the provincial elites, was very delicate. Above all, it depended on peace. The empire was, in fact, exceptionally vulnerable to war and invasion. The defences along its extended borders were not designed to withstand major attacks, while roads ran from them towards cities whose riches lay unprotected by walls. Its armies were by now accustomed to fixed bases and would take some time to deploy, especially if they had to be moved large distances. The subjects of the empire had enjoyed relatively low levels of taxation for decades and the resources needed to meet a challenge could not be easily raised at short notice. (As an excellent survey of these troubled years see David Potter, The Empire at Bay, ad 180-395, London and New York, 2004.)
World History
