The latest from Fjordman explores the development of optics in the West and in the Islamic world:
My history of optics will be published in at least five parts here over the coming days. I will look into all aspects of it, from mathematics via glassmaking, eyeglasses/spectacles, microscopes and telescopes to chemistry, photography and the modern electromagnetic understanding of light. All following quotes by the eminent scholar David C. Lindberg, who is widely recognized to be a leading scholar on ancient, medieval and early modern optics, refer to his book Theories of vision — From al-Kindi to Kepler, except when explicitly stated otherwise. I include page references to longer quotes from all relevant book so that others can use the material if they want to.
Speculations about the rainbow can be traced almost as far back as written records go. In China, a systematic analysis of shadows and reflection existed by the fourth century BC. I will concentrate mainly on the Greek, Middle Eastern and European optical traditions here, but will say a few words about Chinese ideas later. The theories of vision of the atomists Democritus and Epicurus, of Plato and his predecessors, of the Stoics and of Galen and Aristotle were almost entirely devoid of mathematics. The first Greek exposition of a mathematical theory of vision was in the Optica by the great mathematician Euclid, author of the Elements, perhaps the most influential textbook in the history of mathematics. Scholar Victor J. Katz in A History of Mathematics, second edition, page 58:
“The most important mathematical text of Greek times, and probably of all time, the Elements of Euclid, written about 2300 years ago, has appeared in more editions than any work other than the Bible”¦.Yet to the modern reader the work is incredibly dull…There are simply definitions, axioms, theorems, and proofs. Nevertheless, the book has been intensively studied. Biographies of many famous mathematicians indicate that Euclid’s work provided their initial introduction into mathematics, that it in fact exited them and motivated them to become mathematicians. It provided them with a model of how ‘pure mathematics’ should be written, with well-thought-out axioms, precise definitions, carefully stated theorems, and logically coherent proofs. Although there were earlier version of Elements before that of Euclid, his is the only one to survive, perhaps because it was the first one written after both the foundations of proportion theory and the theory of irrationals had been developed in Plato’s school and the careful distinctions always to be made between number and magnitude had been propounded by Aristotle. It was therefore both ‘complete’ and well organized.”
The Elements is a compendium organized from many previously existing texts, but Euclid did give the work an overarching structure. Sadly, almost nothing is known about him personally, but he lived in the early Hellenistic period and was probably born a few years before Archimedes of Syracuse (ca. 287-212 BC). Katz, page 58:
“In any case, it is generally assumed that Euclid taught and wrote at the Museum and Library at Alexandria. This complex was founded around 300 B.C.E. by Ptolemy I Soter, the Macedonian general of Alexander the Great who became ruler of Egypt after the death of Alexander in 323 B.C.E. ‘Museum’ here means a ‘Temple of the Muses,’ that is, a location where scholars meet and discuss philosophical and literary ideas. The Museum was to be, in effect, a government research establishment. The Fellows of the Museum received stipends and free board and were exempt from taxation. In this way, Ptolemy I and his successors hoped that men of eminence would be attracted there from the entire Greek world. In fact, the Museum and Library soon became a focal point of the highest developments in Greek scholarship, both in the humanities and the sciences.”
Even though other, similar works had existed before, Euclid’s version was greatly successful. Copies of it were made for centuries, sometimes with new additions. Katz, page 59:
“In particular, Theon of Alexandria (fourth century C.E.) was responsible for one important new edition. Most of the extant manuscripts of Euclid’s Elements are copies of this edition. The earliest such copy now in existence is in the Bodleian Library at Oxford University and dates from 888. There is, however, one manuscript in the Vatican Library, dating from the tenth century, which is not a copy of Theon’s edition but of an earlier version. It was from a detailed comparison of this manuscript with several old manuscript copies of Theon’s version that the Danish scholar J. L. Heiberg compiled a definitive Greek version in the 1880s, as close to the Greek original as possible. (Heiberg did the same for several other important Greek mathematical texts.) The extracts to be discussed here are all adapted from Thomas Heath’s 1908 English translation of Heiberg’s Greek. Euclid’s Elements is a work in thirteen books, but it is certainly not a unified work.”
Johan Ludvig Heiberg (1854-1928), philologist and historian of mathematics at the University of Copenhagen, Denmark, inspected a manuscript in Constantinople in 1906 which contained previously unknown mathematical works by Archimedes. It is worth noting here that manuscripts from the Byzantine Middle Ages containing very important works could be found in Constantinople (Istanbul), now under Turkish control, yet Turkish Muslims did not show much interest in discovering this.
Archimedes was the first mathematician to derive quantitative results from the creation of mathematical models of physical problems on earth. He was responsible for the first proof of the law of the lever as well as of the basic principle of hydrostatics. The principle of the lever was known before this, but as far as we know no-one had created a mathematical model for it before Archimedes. His genius as an engineer of various military devices kept the Roman invasion forces at bay for months. He was allegedly killed by a Roman soldier after the capture of Syracuse (212 BC), even though the commander Marcellus wanted to spare his life.
Another prominent Greek mathematician was Apollonius. Again, the cited dates of his birth conflict, apart from the fact that he was active in the years before and slightly after 200 BC. Victor J. Katz in A History of Mathematics, page 118:
“Apollonius was born in Perge, a town in southern Asia Minor, but few details are known about his life. Most of the reliable information comes from the prefaces to the various books of his magnum opus, the Conics. These indicate that he went to Alexandria as a youth to study with successors of Euclid and probably remained there for most of his life, studying, teaching, and writing. He became famous in ancient times first for his work on astronomy, but later for his mathematical work, most of which is known today only by titles and summaries in works of later authors. Fortunately, seven of the eight books of the Conics do survive, and these represent in some sense the culmination of Greek mathematics. It is difficult for us today to comprehend how Apollonius could discover and prove the hundreds of beautiful and difficult theorems without modern algebraic symbolism. Nevertheless, he did so, and there is no record of any later Greek mathematical work that approaches the complexity or intricacy of the Conics.”
The number of original scientific works declined during Roman times. Hero or Heron of Alexandria did some optical work, but the greatest optician of antiquity was undoubtedly Claudius Ptolemy, astronomer, mathematician and geographer who flourished in Alexandria during the second century AD. He extended Euclid’s mathematical analysis of vision, and enlarged it to include additional physical and physiological elements. After Ptolemy, the legacy of Greek Antiquity was passed on to medieval times, to the Middle East and to Europe.
According to scholar F. R. Rosenthal: “Islamic rational scholarship, which we have mainly in mind when we speak of the greatness of Muslim civilisation, depends in its entirety on classical antiquity”¦in Islam as in every civilisation, what is really important is not the individual elements but the synthesis that combines them into a living organism of its own”¦Islamic civilisation as we know it would simply not have existed without the Greek heritage.”
Greek knowledge was of vital importance to Muslim scholars in all disciplines, especially in optics. Al-Kindi (d. 873 AD), or Alkindus as he was known in Europe, lived in Baghdad in the ninth century and was close to several Abbasid Caliphs. He was one of the first to attempt reconciling Islam with Greek philosophy, especially with Aristotle, a project that was to last for several centuries and ultimately prove unsuccessful due to religious resistance. In the book How Greek Science Passed to the Arabs, De Lacy O’Leary states that “Aristotelian study proper began with Abu Yusuf Ya’qub ibn Ishaq al-Kindi (d. after 873), commonly known as ‘the Philosopher of the Arabs.’ It is significant that almost all the great scientists and philosophers of the Arabs were classed as Aristotelians tracing their intellectual descent from al-Kindi and al-Farabi.”
Al-Kindi’s De aspectibus was based upon Euclid’s Optica, but was also critical of it in some cases. Al-Kindi’s book on optics influenced the Islamic world for centuries. He was a younger contemporary of al-Khwarizmi (d. ca 850 AD), who also worked in Baghdad, and together they provided an early introduction to the Middle East of the decimal numeral system with the zero which was gradually spreading from India.
The Baghdad-centered Abbasid dynasty, which replaced the Damascus-centered Umayyad dynasty after 750 AD, was closer to Persian culture and was clearly influenced by the pre-Islamic Sassanid Zoroastrian practice of translating works and creating great libraries. Even Dimitri Gutas admits this in his book Greek Thought, Arab Culture. There was still a large number of Persian Zoroastrians as well as Christians and Jews, and they played a disproportionate role in the translation of scholarly works. For instance, the talented mathematician Thabit ibn Qurra (836–901), a member of the Sabian sect, was fluent in Greek, Syriac or Syro-Aramaic as well as in Arabic. Perhaps the most famous translator of all was Hunayn or Hunain ibn Ishaq (808-873), called Johannitius in Latin.
Hunain was a Nestorian (Assyrian) Christian who had studied Greek by living in Greek lands, presumably in the Byzantine Empire, and eventually settled in Baghdad. Since he was a contemporary of al-Kindi in Baghdad and employed by the same patrons, they were probably acquainted. Soon he, his son and his nephew had made available in Arabic and Syriac Galen’s medical treatises as well as Hippocrates and texts by Aristotle, Plato and others. In some cases, he apparently translated a work into Syriac and his son Ishaq translated this further into Arabic. Hunain wrote as well as translated scientific works, and his own compositions include two on ophthalmology: the Ten Treatises on the Eye and the Book of the Questions on the Eye. His books were influential in the Islamic world and in Europe, but he transmitted an essentially pure Galenic theory of vision.
By far the most important optical work to appear during the Middle Ages was the Book of Optics (Kitab al-Manazir in the original Arabic; De Aspectibus in Latin translation). It was written during the first quarter of the eleventh century by Ibn al-Haytham (965–ca. 1039), who was born in present-day Iraq but spent much of his career in Egypt. He is known as Alhazen in Western literature. David C. Lindberg, page 60:
“Abu ‘Ali al-Hasan ibn al-Haytham (known in medieval Europe as Alhazen or Alhacen) was born in Basra about 965 A.D. The little we know of his life comes from the biobibliographical sketches of Ibn al-Qifti and Ibn Abi Usaibi’a, who report that Alhazen was summoned to Egypt by the Fatimid Khalif, al-Hakim (996-1021), who had heard of Alhazen’s great learning and of his boast that he knew how to regulate the flow of the Nile River. Although his scheme for regulating the Nile proved unworkable, Alhazen remained in Egypt for the rest of his life, patronized by al-Hakim (and, for a time, feigning madness in order to be free of his patron). He died in Cairo in 1039 or shortly after. Alhazen was a prolific writer on all aspects of science and natural philosophy. More than two hundred works are attributed to him by Ibn Abi Usaibi’a, including ninety of which Alhazen himself acknowledged authorship. The latter group, whose authenticity is beyond question, includes commentaries on Euclid’s Elements and Ptolemy’s Almagest, an analysis of the optical works of Euclid and Ptolemy, a resume of the Conics of Apollonius of Perga, and analyses of Aristotle’s Physics, De anima, and Meteorologica.”
Alhazen did work in many scholarly disciplines but is mostly remembered for his contributions in optics. He read Hippocrates and Galen on medicine, Plato and Aristotle on philosophy, was familiar with the major works in Greek mathematics and wrote commentaries on Apollonius, Euclid, Ptolemy and Archimedes’ On the Sphere and Cylinder. As for optical sources, he was probably familiar with al-Kindi’s De aspectibus and Hunain ibn Ishaq’s Ten Treatises. He had the resources to develop a theory of vision which incorporated elements from all the optical traditions of the past. Although he relied heavily on the Greek scientific tradition, the synthesis which he made was new. Lindberg, page 85:
“Alhazen’s essential achievement, it appears to me, was to obliterate the old battle lines. Alhazen was neither Euclidean nor Galenist nor Aristotelian — or else he was all of them. Employing physical and physiological argument, he convincingly demolished the extramission theory; but the intromission theory he erected in its place, while satisfying physical and physiological criteria, also incorporated the entire mathematical framework of Euclid, Ptolemy, and al-Kindi. Alhazen thus drew together the mathematical, medical, and physical traditions and created a single comprehensive theory.”
Curiously enough the Book of Optics was not widely known and used in the Islamic world. There were a few notable exceptions, prominent among them the Persian natural philosopher Kamal al-Din al-Farisi (1267-ca.1320) in Iran, who made the first mathematically satisfactory explanation of the rainbow. Similar ideas were articulated at roughly the same time by the German theologian and physicist Theodoric of Freiberg (ca. 1250 –1310). These two scholars apparently had nothing in common, apart from the fact that both were inspired by Alhazen. Here is David C. Lindberg in The Beginnings of Western Science, second edition, page 184:
“Kamal al-Din used a water-filled glass sphere to simulate a droplet of moisture on which solar rays were allowed to fall. Driven by his observations to abandon the notion that reflection alone was responsible for the rainbow (the traditional view, going back to Aristotle), Kamal al-Din concluded that the primary rainbow was formed by a combination of reflection and refraction. The rays that produced the colors of the rainbow, he observed, were refracted upon entering his glass sphere, underwent a total internal reflection at the back surface of the sphere (which sent them back toward the observer), and experienced a second refraction as they exited the sphere. This occurred in each droplet within a mist to produce a rainbow. Two internal reflections, he concluded, produced the secondary rainbow. Location and differentiation of the colored bands of the rainbow were determined by the angular relations between sun, observer, and droplets of mist. Kamal’s theory was substantially identical to that of his contemporary in Western Europe, Theodoric of Freiberg. It became a permanent part of meteorological knowledge after publication by RenÃ© Descartes in the first half of the seventeenth century.”
Alhazen personally should be credited with being one of the greatest scholars of his age, yet his scientific mindset wasn’t always appreciated by his contemporaries. Here is how his writings were received by fellow Muslims, as quoted in Ibn Warraq’s modern classic Why I Am Not a Muslim, page 274:
“A disciple of Maimonides, the Jewish philosopher, relates that he was in Baghdad on business, when the library of a certain philosopher (who died in 1214) was burned there. The preacher, who conducted the execution of the sentence, threw into the flames, with his own hands, an astronomical work of Ibn al-Haitham, after he had pointed to a delineation therein given of the sphere of the earth, as an unhappy symbol of impious Atheism.”
Alhazen’s groundbreaking Book of Optics survives to us in Latin translation. Muslims had access to ideas but failed to appreciate them and exploit their potential. It was in the West that Alhazen had his greatest influence. The book was translated into Latin and had a significant impact on the English scholar Roger Bacon (ca. 1220–1292) and others in the thirteenth century. Bacon was educated at Oxford and lectured on Aristotle at the University of Paris. He wrote about many subjects and was among the first persons to argue that lenses could be used for the correction of eyesight, which was eventually done in the late 1200s in Europe. His teacher, the English bishop and scholar Robert Grosseteste (ca. 1170–1253), was an early proponent of validating theory through experimentation. Grosseteste played an important role in shaping Oxford University in the first half of the thirteenth century, with great intellectual powers and administrative skills. As John North says in God’s Clockmaker, page 30:
“Robert Grosseteste was the most influential Oxford theologian of the thirteenth century. Like [Alexander] Neckham he applied his scientific knowledge to theological questions, but — unlike Neckham — he had a very original scientific mind. He had much astronomical and optical knowledge; and, without having a very profound knowledge of mathematics, he appreciated its importance to the physical sciences. There was nothing especially new in this, although it was a principle that had been largely overlooked in the West. It did no harm to have the principle proclaimed repeatedly by Grosseteste’s leading advocate after his death, the Franciscan Roger Bacon, lecturer in both Oxford and Paris.”
Directly or indirectly, the Book of Optics inspired much of the activity in optics that occurred between the thirteenth and the seventeenth centuries, including Bacon, Witelo, John Pecham and the Italian scholars Giambattista della Porta (1535-1615), who helped popularize the camera obscura, and Francesco Maurolico (1494-1575), a mathematician, astronomer and monk who did work on the refraction of light and studied the camera obscura.
Pecham and Witelo had access to a number of works, including those of Bacon and Alhazen, and contributed considerably to the dissemination of their ideas. Witelo (born ca. 1220, died after 1280) was a Polish scholar and friend of the Flemish scholar William of Moerbeke (ca. 1215-1286 AD), the translator of Aristotle’s works from the original Greek. Witelo’s major surviving work on optics, Perspectiva, completed in the 1270s (and deeply inspired by Alhazen), was dedicated to William. The Englishman John Pecham (d. 1292 AD), Archbishop of Canterbury, studied optics and astronomy and was influenced by Bacon’s work.
Late medieval optical theory was incorporated into the university curriculum. What is unique about optics in Europe is that it was also applied to art, something which was entirely absent in the Islamic world. David C. Lindberg in Theories of vision — From al-Kindi to Kepler, page 147-148:
“About 1303, a little more than a decade after the deaths of Roger Bacon and John Pecham, Giotto di Bondone (ca. 1266-1337) began work on the frescoes of the Arena Chapel in Padua — paintings that later generations would view as the first statement of a new understanding of the relationship between visual space and its representation on a two-dimensional surface. What Giotto did was to eliminate some of the flat, stylized qualities that had characterized medieval painting by endowing his figures with a more human, three-dimensional, lifelike quality; by introducing oblique views and foreshortening into his architectural representations, thereby creating a sense of depth and solidity; and by adjusting the perspective of the frescoes to the viewpoint of an observer standing at the center of the chapel. This was the beginning of a search for ‘visual truth,’ an ‘endeavor to imitate nature,’ which would culminate a century later in the theory of linear perspective. Historians of art are unanimous in crediting the invention of linear perspective to the Florentine Filippo Brunelleschi (1377-1446). Although Brunelleschi left no written record of his achievement, his disciple Antonio Manetti gives us an account in his Vita di Brunelleschi.”
The techniques that Brunelleschi used were given a theoretical expression in the treatise Della pittura, written about 1435 by Leon Battista Alberti (1404-72) and dedicated to Brunelleschi. Significantly, at about this time, new flat glass mirrors were available and replaced the older flat metal and hemispherical glass mirrors. Giotto painted with the aid of a mirror, and Brunelleschi used a plane mirror in his perspective demonstration. Lindberg, page 152:
“What is beyond conjecture is that the creators of linear perspective knew and utilized ancient and medieval optical theory. Alessandro Parronchi has argued that Brunelleschi’s friend Paolo Toscanelli brought a copy of Blasius of Parma’s Questiones super perspectivam to Florence when he returned from Padua in 1424 and that Brunelleschi could also have had access to the works of Alhazen, Bacon, Witelo, and Pecham. He argues, moreover, that these works may have played a decisive role in the working out of Brunelleschi’s perspective demonstration. We are on much surer ground with Alberti, whose description of the visual pyramid clearly reveals knowledge of the perspectivist tradition. Moreover, Alberti’s reference to the central ray of the visual pyramid as that through which certainty is achieved can only come from Alhazen or the Baconian tradition.”
Renaissance Europe became the first civilization to institute the regular use of human dissection for scientific purposes. This was integrated into the medical education. The Italian polymath Leonardo da Vinci (1452–1519) performed dissections in order to gain a better grasp of anatomy, and famously displayed his studies of the proportions of the human body in drawings such as the Vitruvian Man. He did make use of optical treatises, but he was isolated and without influence in the field. Most of his manuscripts were in private hands until 1636 and were not seriously studied until the late eighteenth century.
Friedrich Risner (d. 1580), a German mathematician who spent most of his scholarly career at the University of Paris, published a well-edited printed edition of the works of Alhazen and Witelo in 1572, the Opticae thesaurus, which benefited leading seventeenth-century figures such as Kepler, Huygens and Descartes. Allegedly, Risner was among the first to suggest the use of a portable camera obscura in the form of a lightweight wooden hut. Previously, a camera obscura (Latin: “dark chamber”) was the size of a room, with a tiny hole in the wall or the roof. Kepler tested a tent-size portable camera obscura for astronomical observations in the early 1600s, but the earliest reference to a small portable box camera came in the second half of that century. The use of the camera obscura as an aid to painters and artists was virtually nonexistent in the Islamic world, but indirectly led to the development of box cameras used for photography in nineteenth century Europe.
The German astronomer Johannes Kepler (1571–1630) became seriously interested in optics even before the telescope had been invented. He worked with the last of the great pre-telescopic observers, the Dane Tycho Brahe (1546–1601), and had probably received an introduction to the subject at the university. Kepler, like Alhazen before him, was primarily a mathematician and did not study the anatomy of the eye, but his description does not contain any major errors. He had as much anatomical knowledge as he needed to develop his theory of the retinal image. Lindberg, page 202:
“He has painstakingly demonstrated that all the radiation from a point in the visual field entering the eye must be returned to a point of focus on the retina. If all the radiation entering the eye must be taken into account (and who could gainsay that proposition after reflecting on Kepler’s argument?), and if the requirement of a one-to-one correspondence between the point sources of rays in the visual field and points in the eye stimulated by those rays is accepted, then Kepler’s theory appears to be established beyond serious dispute. An inverted picture is painted on the retina, as on the back of the camera obscura, reproducing all the visual features of the scene before the eye. The fact that Kepler’s geometrical scheme perfectly complemented Platter’s teaching about the sensitivity of the retina surely helped to confirm this conclusion. It is perhaps significant that Kepler employed the term pictura in discussing the inverted retinal image, for this is the first genuine instance in the history of visual theory of a real optical image within the eye — a picture, having an existence independent of the observer, formed by the focusing of all available rays on a surface.”
Kepler compared the eye to a camera obscura, but only once in his treatise. The most difficult challenge was the fact that the picture on the retina is upside down and reversed from right to left. This inverted picture caused Kepler considerable problems. He lacked the means to cope with this issue, but argued that “geometrical laws leave no choice in the matter” and excluded the problem from optics, separating the optical from the nonoptical aspects of vision, which was the sensible thing to do. Optics ceases with the formation of the picture on the retina. What happens after that is for somebody else to find out. The image gets turned “right” by the brain, but the functions of the brain were not understood by any culture at that time. The term “neurology” was coined by the English doctor Thomas Willis (1621–1675).
Although Kepler’s theory of the retinal image is correctly identified as the birth of modern optical theory, Lindberg argues that he was the culminating figure of centuries of scholarship. Theories of vision, page 207-208:
“That his theory of vision had revolutionary implications, which would be unfolded in the course of the seventeenth century, must not be allowed to obscure the fact that Kepler himself remained firmly within the medieval framework. The theory of the retinal image constituted an alteration in the superstructure of visual theory; at bottom, it remained solidly upon a medieval foundation. Kepler attacked the problem of vision with greater skill than had theretofore been applied to it, but he did so without departing from the basic aims and criteria of visual theory established by Alhazen in the eleventh century. Thus neither extreme of the continuity-discontinuity spectrum will suffice to describe Kepler’s achievement: his theory of vision was not anticipated by medieval scholars; nor did he formulate his theory out of reaction to, or as a repudiation of, the medieval achievement. Rather, Kepler presented a new solution (but not a new kind of solution) to a medieval problem, defined some six hundred years earlier by Alhazen. By taking the medieval tradition seriously, by accepting its most basic assumptions but insisting upon more rigor and consistency than the medieval perspectivists themselves had been able to achieve, he was able to perfect it.”
In the appendix section to his book, David C. Lindberg argues that the Book of Optics must have been translated during the late twelfth or early thirteenth century. There is insufficient evidence to demonstrate clearly who translated it from Arabic, but indirect evidence indicates Spain as the point of translation, and the high quality of translation points to the great Italian (Lombard) translator Gerard of Cremona (ca. 1114–1187) or somebody from his school. Many of the works initially translated from Arabic by Gerard and his associates, among them Ptolemy’s Almagest, were later translated directly from Greek into Latin from Byzantine manuscripts. The version of Ptolemy’s astronomy that was used by Copernicus came from Greek manuscripts, not Gerard’s translations. Obviously, Alhazen’s work had to be translated from Arabic since it was written in that language in the first place.
As mentioned above, optical theory was widely utilized by artists in Europe to create mathematical perspective. Leonardo da Vinci’s most famous painting is undoubtedly the Mona Lisa, which is now in the MusÃ©e du Louvre in Paris, but The Last Supper, finished in 1498 in the Convent of Santa Maria delle Grazie in Milan, Italy, runs a close second. The story it tells is narrated in the Gospel of John 13:21 in the New Testament, with the first celebration of the Eucharist, when Jesus announces that one of his Twelve Apostles will betray him. The picture is a great example of one point perspective, with Christ’s head as the midpoint of the composition.
Albrecht DÃ¼rer (1471–1528) was a German printmaker, painter and artist-mathematician from Nuremberg and one of the leading figures of the Northern Renaissance. He spent several years in Italy to study the art of perspective, and had to develop a mathematical terminology in German because some of it did not yet exist at the time. His Vier BÃ¼cher von menschlicher Proportion, or Four Books on Human Proportion, from 1528 was dedicated to the study of human proportions. Like Leonardo, he was inspired by the Roman architect Vitruvius, but he also did extensive empirical research on his own. The examples of DÃ¼rer, Leonardo and others demonstrate that there was much geometry and mathematical theory behind the more accurate representation of human figures on canvas in post-Renaissance European art.
It is true that you can find elements of perspective among the ancient Greeks, and sporadically in Indian, Chinese, Korean, Japanese and other artistic traditions. One prominent example is the masterpiece Going Up the River or Along the River During the Qingming Festival by the Chinese painter Zhang Zeduan (1085-1145 AD). The painting, which is sometimes referred to as China’s Mona Lisa, depicts the daily life of the Song Dynasty capital Kaifeng with geometrically accurate images and great attention to detail. The work masters some techniques related to shading and foreshortening, but these experiments were later abandoned and not developed further. East Asian art tended to consider images as a form of painted poetry. Alan Macfarlane and Gerry Martin explain in Glass: A World History, page 59-60:
“It is well known that Plato felt that realist, illusionary art should be banned as a deceit, and most civilisations have followed Plato, if for other reasons. For the Chinese (and Japanese) the purpose of art was not to imitate or portray external nature, but to suggest emotions. Thus they actively discouraged too much realism, which merely repeated without any added value what could anyway be seen. A Van Eyck or a Leonardo would have been scorned as a vulgar imitator. In parts of Islamic tradition, realistic artistic representations of living things above the level of flowers and trees are banned as blasphemous imitations of the creator’s distinctive work. Humans should not create graven images, or any images at all, for thereby they took to themselves the power of God. Again, Van Eyck or Leonardo would have been an abhorrence. Even mirrors can be an abomination, for they create duplicates of living things.”
The Chinese had a passion for mirrors, but of the highly polished bronze variety. These were often believed to have magical properties, could be made into plane, convex or concave shapes and were sometimes used for optical experiments. Japanese mirrors were traditionally made of brass or steel, not glass, and were used as sacred symbols, to look into the soul instead of the body. The Romans knew how to make glass mirrors, but metal mirrors were preferred. Fine mirrors (as produced in Venice) were never made in the medieval glass traditions of Islam, possibly for religious reasons. The development of flat glass and metal mirrors combined with the study of optics led to a new kind of art in Renaissance Europe. That the mirror played a part in the development of linear perspective is a theme taken up by the scholar Samuel Edgerton. Macfarlane and Martin, page 63-64:
“Mirrors had been standing in artists’ studios for several hundred years, for example Giotto had painted ‘with the aid of mirrors’. Yet Brunelleschi’s extraordinary breakthrough is the culminating moment. Without what Edgerton calculates to be a twelve-inch-square flat mirror, the most important single change in the representation of nature by artistic means in the last thousand years could not, Edgerton argues, have occurred. Leonardo called the mirror the ‘master of painters’. He wrote that ‘Painters oftentimes despair of their power to imitate nature, on perceiving how their pictures are lacking in the power of relief and vividness which objects possess when seen in a mirror”¦’ It is no accident that a mirror is the central device in two of the greatest of paintings — Van Eyck’s ‘Marriage of Arnolfini’, and Velazquez’s ‘Las Meninas’. It was a tool that could be used to distort and hence make the world a subject of speculation. It was also a tool for improving the artist’s work, as Leonardo recommended.”
The Flemish painter Jan van Eyck (ca. 1395–1441) is strongly associated with the development of oil painting, yet he did not invent the medium. The Islamic Taliban regime destroyed two ancient Buddha statues in the Afghan region of Bamiyan in 2001. Recent discoveries indicate that Buddhists made oil paintings in this region already in the mid-seventh century AD. Nevertheless, the perfection of oil by van Eyck and others allowed depth and richness of color, and Dutch and Flemish painters in the fifteenth century were the first to make oil the preferred medium. One masterpiece of Jan van Eyck is the altarpiece in the cathedral at Ghent, the Adoration of the Lamb, from 1432. Another is The Arnolfini Portrait or Marriage of Arnolfini, presumably from the Flemish city of Bruges in 1434.
It is possible that this painting inspired another masterpiece, Las Meninas (The Maids of Honor) from Madrid in 1656, painted by the great Spanish artist Diego VelÃ¡zquez (1599–1660). Born in Seville, Andalusia, VelÃ¡zquez came from a part of the Iberian Peninsula which had been under Islamic rule for many centuries, yet Islamic Spain never produced a painter of his stature. Christian Spain did. Las Meninas displays a highly accurate handling of light and shade as well as of linear perspective. A reflecting mirror occupies a central position in the picture, just like in Marriage of Arnolfini. The mirror also gave the artist a third eye so that he could see himself. Without a good mirror, many great self-portraits, culminating in the series by Rembrandt (1606–1669) during the Dutch Golden Age, could not have been made.