The Attraction of Ibn al-Haytham’s Optics

by Charles Burnett Published on: 4th September 2023

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The Optics (kitāb al-Manāzir or Perspectiva/De aspectibus of Abū ʿAlī ibn al-Haytham al-Ḥasan ibn al-Ḥasan (ca. 965-1040) is one of the foundational works in the history of science. It was written between 1028 and 1038 in Cairo and had a distribution in the Islamicate world, and even more so in Western Christendom, after its translation into Latin in the late 12th or early 13th century under the name ‘Alhazen’ or ‘Alhacen’.

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“The Optics of Ibn al-Haytham Books IV–V On Reflection and Images Seen by Reflection” Abdelhamid I. Sabra, Prepared for publication by Jan P. Hogendijk

Its seven books treat of the function of the eye, direct vision, reflection and images seen by reflection, refracted light and false images. It is known for its description and demonstration of the scientific method – principles on which all reliable scientific experimentation should be based; for its establishment of the intromission theory of vision, whereby the eye receives rays directly from the object of sight, rather than sending out a spirit to retrieve the image of the object; and its account of the camera obscura whose concept was eventually realised in photography; as well as many other aspects. In the East it was revised by Kamāl al-Dīn al-Fārisī (1267-1319) in his Tanqī al-Manāzir (‘Revision of the Optics’). In the West it was influential on the optical writings of Roger Bacon (ca.1220-ca.1292), John Pecham (ca. 1230-1292), and Erazmus Ciolek Witelo (Vitello; ca. 1230 – ca. 1280), who in turn wrote a revision. Apparently, it suffered a decline in the fourteenth and fifteenth centuries (though it was translated into Italian in the late fourteenth century). But it was revived by Friedrich Risner  (ca. 1533-1580), who published the medieval Latin translation for the first time in 1572. This enabled Johannes Kepler (1571-1630) and René Descartes (1596-1650) to use it extensively in their own works on optics.

One may say that it suffered a second decline until the early twentieth century when various members of the Warburg Institute expressed interest in the text, especially its Arabic original, and Abdulhamid Ibrahim Sabra (1924-2013) was encouraged to edit the Arabic text, along with an English translation. Editions of the Arabic text were published by the National Council for Culture, Arts and Letters in Kuwait (books 1-3 in 1983, and books 4-5 in 2002). Two volumes of his English translation were published by the Warburg Institute covering books 1-3 of the seven-volume work (Warburg Institute, University of London, 1989).[1] In celebration of the imminent publication of a third volume, covering books 4 and 5, it would be interesting to rehearse the desires of successive scholars to see critical editions of the Arabic Latin texts, i.e. to explore the attraction of Ibn al-Haytham.

It would be superfluous to describe the contents and the impact of the Optics, since this has been fully explored in other sources, including articles and video presentations in Muslim Heritage (e.g. those of Nader El-Bizri, Charles Falco and Saira Malik). Instead, this article introduces, for the first time in translation, Friedrich Risner’s own advocacy of the Optics, in his monumental edition of Ibn al-Haytham’s work (along with that of Vitello). The full-page title immediately puts the work on a pedestal: ‘A Treasury of Optics (Opticae thesaurus). The seven books of Alhazen the Arab, now for the first time made public (editi); the books on dawn and dusk and the rising of the clouds, of the same author. Likewise, the ten books of Vitello of Zurich. All these revived (instaurati), illustrated and augmented with figures, with commentaries on Alhazen added by Friedrich Risner’. On the verso of the title page is the famous illustration of all the aspects of optics that Ibn al-Haytham deals with, under the caption: ‘The arguments of the three-fold sight – direct, reflected and refracted – about which optics disputes’ (Triplicis visus directi reflexi refracti de quo optica disputat argument).

Illustration: Triplicis uisus, directi, reflexi, & refracti, de quo optica disputat, argumenta. From Opticæ thesaurus, 1572, by Alhazen (965-1039). GC5 R4947 572i, Houghton Library, Harvard University (Wikipedia)

The preface begins with the dedication to Catherine de’ Medici (1519-1589), wife of the French king Henry II (1547-1559) and regent (or power behind the throne) for their sons, Francis II (1559-1560), Charles IX (1560-1574) and Henry III (1574-1589). At the time of this dedication (1572) she was at the height of her power, and a great patron of the arts and humanities. In 1572 Risner had been in Paris for several years, as an assistant to Petrus Ramus,[2] who was a Regius Professor at the College Royale de France, to which Risner himself was appointed to the first chair of mathematics in 1576. This period was a particularly turbulent period because of attacks between Catholics and Protestants, culminating in the St Batholomew’s Day Massacre, which occurred in August of the same year as the publication. The book, however, was not published in Paris, but ‘by imperial and royal privilege’ in Basel by Nicolaus and Eusebius Episcopius (Bischoff), who are well known for their publications of works by Erasmus and Agricola. This is the translation of the complete preface:

More people adore the rising Sun, illustrious queen, than the setting, as is popularly said, but it should have been the other way round in my opinion, since the setting of the Sun has embraced the richest and most prosperous parts of this world, such as America under the Equator, and the most fortunate Spice Islands.[3] So also, in human life, if any age is particularly praiseworthy it is old age (senectus), the governor and master of the previous ages.[4] Therefore, this advice for honouring your greatness from Petrus Ramus occurred to me. When he (Ramus) consecrated to your name the liberal arts in the French language, he invited many mortals, by following his example, to conceive and name the same ideas, as if he judged you in France not only to be the mother most worthy for such a great King (Chales IX) but the most beloved patron of all royal virtues and praises.

Thus, I call Alhazen, as it were a client of yours, and I name him the Arabic (writer) on optics, as is understood from his Arabic name Alhazen (which in Latin means ‘good man’), and the inscription of the work indicates that he was born from an Arabic father <called> Alhayzan. I have learnt from experts in Arabic that there were four Arabic philosophers with this name, but I have not yet been able to know for certain either by reading or enquiry, at what time our Alhazen flourished. Nevertheless, I notice that he is held by leading mathematicians to be among the number of the oldest Arabs. Although there is no mention of the time when he lived, a certain guess is that he lived in about the 1100th year of Christ, which is, of course, the period of Avicenna, Averroes, Zoara (Ibn Zuhr?)[5] and other excellent Arabs. In this century it is quite clear from the commentaries, among the Arabs and Saracens, both the studies of all the noble and especially the mathematical disciplines flourished. This author (whose publication by most renowned mathematicians we have been awaiting for 30 years), when P(etrus) Ramus, having searched for all traces of him for a long time through various libraries, finally bought him <displayed like a> prostitute in a public auction and, in short, considered as abandoned (pro deserto). Afterwards, he obtained another copy and handed over both to me (whom he had had as a companion and helper in mathematical exercises for some years before) to collate. When in the middle of the heat of the mounting hostilities[6] he took out from his library certain mathematical (works) that were more precious to him, and especially this Alhazen, and brought me with him to Basel with these, as it were, household gods (penates), he occupied a whole year in restoring and giving form to the author. I certainly recognized a wonderful diligence and doctrine in the Arabic man, not a little, as I was able to notice, helped by the old Greek optical <writers>. Here there is nothing Euclidean or Ptolemaic,[7] <but> he had perhaps taken something from Archimedes, Apollonius and Avenellus, [8] whom the monuments of literature attest wrote certain optical works. Likewise, from Damianus[9] and other opticians, whose books have not yet fallen into my hands. Alhazen himself admits the reading of the old opticians in book 6, chapter 4, <writing> about the error which happens in convex spherical mirrors, and in book 7, chapter 6, how sight comprehends visible things through refraction.

Therefore, when I had thoroughly investigated a brilliant writer and an eloquent but confused optician, I took the advice of what Petrus Ramus, as a persuader and author <gave> me, which is the following: First, because the whole work had been divided into a few, wordy chapters, with a continuous and never-ending narrative, I divided single books and chapters into propositions, and noted which theorems of Vitello corresponded to these, so that, by comparing the theorems of both, the optical matter, being rather difficult and obscure to the beginner and novice reader, should receive light and perspicuity.  Then, I emended and restored all the demonstrations; I added their supports and corroborations (which were lacking for all in many places) from Euclid, Theodosius, Apollonius, Serenus and other geometers. Especially in the case of the fifth and sixth books in which catoptrics are included, and the seventh, which explains refraction, because of the obscurity and brevity of the demonstrations, I tried to illustrate them by certain little commentaries. In doing this I have decided that nothing at all should be changed except that, for those <words> which seemed to bring to things obscurity and ambiguity, I substituted other words. So, the inscription of the work (which for the author was ‘De aspectibus’) I name ‘Optica’ from the Greek, being a more elegant and shorter word.

But, most famous queen, I would seem not forgetful perhaps of my duty, but certainly not sufficiently remembering your majesty – I who in that preface dispute with you so many scholastic things in such a scholastic way – unless I offered such a singular benefit, and such a popular and royal gift to all schools and scholars in your name. For, although the benefits and gifts of outstanding kings and queens towards their people should be many, certainly nothing can be given more magnificent or regal in its virtue and doctrine. And, indeed, if this were a place for any rhetorician to declaim the use of optics, it would seem to him to be a marathon field, whether those high parts of the world or these low parts are considered. For, whatever is open and revealed to humans concerning the matter, number, order and infinite variety of the movements of the celestial bodies, optics has almost opened and revealed: it has understood and it has convinced by optical skill meteora (atmospheric phenomena), the wonderful things in one rainbow distinguished especially by optical rays; and the false opinions about the number, movement and place of the elements.

But in the life of humans many things attributed to the tricks of demons – like representing mobile images in some (part of the) air, such as seeing an army separated by a long distance as if before the eyes; like destroying a fleet of the enemy by fire[10] – all these are done by the force and facility of the optical art. For the time being I shall be silent about the fact that a painting, a <piece of> architecture or engineering are nothing except optics. Therefore, because Alhazen, the oldest and fullest writer on optical doctrine, dragged from such long darkness, having had the squalor, mould and dust wiped off him, may come forth into the light of the public; because he might enter the mathematical schools; because he might share his discoveries in the public studies, let the fame and glory of Catherine de’ Medici be immortal forever!

Although there is some hyperbole here, as befits a dedication, there is no doubt of the interest of two of the most advanced mathematicians of the day, Petrus Ramus and Friedrich Risner, in Ibn al-Haytham’s Optics. The one sought out manuscripts of the work, the other collated the manuscripts and produced a commented edition. They studied the text together. Moreover, Risner added Vitello’s Optics, which acted as a kind of alternative text to Ibn al-Haytham’s Optics: the one could explain the other, just as al-Fārisī’s text helped to explain and fill in the lacuna of Ibn al-Haytham’s Optics in the Arabic. Finally, the text was dedicated to an arts-loving Queen, and destined for education.

Nearly four hundred years there was a similar interest, centred on the Warburg Institute.[11] It is summarised in a letter sent by the Director, Ernst Gombrich, to Abdulhamid Sabra (known to his colleagues as Bashi Sabra), inviting him to take up a fellowship at the Institute, on 5th June 1962:

This Institute has been founded to study the transmission of ancient culture to the modern world and we are all aware of the immense importance of Arabic scholarship in the preservation and development of Greek science. Some of my colleagues and I have had occasion in the course of our research to appreciate the significance of the Arabic tradition in the fields of optics and geometry, and we all felt the need of more knowledge and research in this important field. It was therefore with genuine enthusiasm that we heard of the hope of being able to fill this gap. We were thrilled to hear that you would work on Ibn al-Haytham, who is only known to us in a very unsatisfactory Latin translation of the sixteenth century which sometimes fails to make sense at all.[12]

The interest went back at least to Fritz Saxl (1890-1948), Warburg’s librarian, who brought the library to London in 1933, in a letter to Eilhard Wiedemann (1852-1928), the historian of Arabic/Islamic science and engineering, of October 10, 1920. Referring to Julius von Schlosser’s Ghibertis Denkwürdigkeit (Berlin, 1912), he claimed that Alhazen was ‘one of the important sources of the early Renaissance’ (‘eine der Hauptquellen der Frührenaissance’) and went on to place Ibn al-Haytham in the tradition of the transmission of ideas from Greek through the Arabic world:

To be able to follow the line which leads from Greece over the Orient to the Renaissance, it would be of great interest for the historian of art to experience whether it is possible to recognize the source of Alhazen for the relevant chapter (on ‘proportion’).[13]

Sabra, of course, took up the fellowship and remained at the Warburg Institute from 1962 to 1972, working hard on his edition and translation of the Optics. Ibn al-Haytham was the topic of several lectures and seminars at the Warburg Institute, e.g. that of 30 October, 1963: ‘The Meeting of East and West: Ibn al-Haytham and the History of Scientific Method’; a seminar on ‘Perspective’, involving Sabra and Graziella Federici Vescovini (who had studied the Italian translation of the Optics) and Robert Klein; and a seminar led by Sabra and Otto Kurz on the sources and legacy of Islamic civilization in 1966-7. Sabra wrote the article on Ibn al-Haytham in the Dictionary of Scientific Biography, in which he quoted Ibn al-Haytham as saying that truth was to be had only in ‘doctrine whose matter was sensible and whose form was rational’. The English translation of books one to three of the Optics was the result of Sabra’s period at the Warburg Institute. Let us hope that the publication of the next volume, Sabra’s translation of books four and five, which was made possible through a generous grant from the Foundation of Science, Technology and Civilisation, will prepare the way for the eventual publication of books six and seven in both Arabic and English.


[1] The Latin text of books 1-5 has been critically edited, with English translation and commentary, by A. Mark Smith: Alhacen’s Theory of Visual Perception and Alhacen on the Principles of Reflection, Philadelphia, 2001 and 2006.
[2] See Mordechai Feingold, The Influence of Petrus Ramus: Studies in Sixteenth and Seventeenth Century Philosophy and Sciences, Basel, 2001.
[3] He means that, by the time the Sun has reached its setting point it has passed over both the Moluccas (in the East) and South America, well known for the supposed riches of Eldorado, whose fame was particularly strong in the late 1500s.
[4] By 1572 Catherine de’Medici was 53 years old.
[5] Risner is referring to the so-called ‘Golden Age’ of Arabic-Islamic culture, to which Avicenna (980-1037), Avenzoar (Zoara; 1094-1162) and Averroes (1126-1198) belonged.
[6] A reference to the clashes between the Protestants (Huguenots) and Catholics.
[7] Both Euclid and Ptolemy had written works on optics, and, contrary to what Risner implies, Ptolemy’s Optics was a source for Ibn al-Haytham.
[8] It is uncertain who this ‘Avenellus’ is.
[9] Damianus of Larissa, 5th-6th cent. AD, wrote an Optical Hypotheses, but is otherwise unknown and obscure.
[10] This is one thing illustrated by Risner’s frontispiece illustration.
[11] For the following information, I am very grateful to Claudia Wedepohl and the services of the Archives of the Warburg Institute.
[12] Warburg Institute Archive (WIA), General Correspondence (GC), Ernst H. Gombrich to Abdulhamid Sabra, 5 June 1962. The reference is, of course, to Risner’s edition of 1572, but Gombrich is mistaken in saying that the translation in this volume dates from this period, rather than from the later twelfth century or early thirteenth century.
[13] ‘Um die Linie, die von Hellas über den Orient nach der Renaissance führt, verfolgen zu können, wäre es nun für den Kunsthistoriker von grössten Interesse, zu erfahren, ob es möglich ist, die Quelle Alhazens für das betr. Kapitel zu erkennen.’

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