DELETED TEXT IN A MANUSCRIPT. GALEN ON THE EYE AND THE MARC. GR. 276.

Abstract

It is very rare for a scribe to cross out text he has just written unless he is correcting a mistake in copying; one would expect editorial matters, e.g. the content of a volume, to be decided well in advance before the book was in production, and any doubts about the content or the authorship of a treatise were commonly annotated in the margins of a manuscript rather than in the main body of the text. This article, however, discusses an entire paragraph that was deleted by the first hand.1 This fragment in the fourteenth century Marcianus gr. 276 is listed as the sole witness of Galen’s lost text on eye diseases, πeρὶ τῶν ἐν ὀφθαλμoῖς παθῶν διάγνωσις, in Diels’ catalogue of medical manuscripts.2 At first sight the passage in question resembles any other manuscript of the period, but both the fact that it was crossed out and its content are very unusual. The manuscript is a miscellaneous collection of medical works and the fragment is preceded and followed by a Galenic work, de atra bile and de causis respirationis. It consists of a title «Galen on the diagnosis of the diseases of the eye», and then six lines of text which ends abruptly. It appears that the scribe began to write the text and realized after a few lines that it was not worth copying. He then crossed it out vehemently and started to write down the next treatise. It would not be surprising to find a text with the title On the diagnosis of the diseases of the eye amongst Galenic works. We know from autobiographical evidence and from cross references in other books that Galen wrote a tract with this title; the Greek original is lost but some Arabic manuscripts transmit what may very well be an epitome of the lost work;3 moreover an Armenian manuscript4 contains a text that would match the description, but it has not yet been edited. The most reliable information is provided by Galen himself; he writes in his de libris propriis that he gave a «book on the diagnosis of eye diseases» to a «young man who treated the eye»; it is said to be a «brief book» like the one «on the anatomy of the womb».5 We learn more about its content from another Galenic work, de locis affectis, where it is said that the specific treatise on the eye lists the names of the diseases, whereas their causes (αἰτίαι) are described in de symptomatum causis.6 Indeed, the latter contains7 a comprehensive and detailed chapter on the most frequent ophthalmic disorders. Another important source – although much later and written in a different cultural context – is the Risala of unain ibn Isḥāq, who mentions two Galenic texts on the eye. The information he provides is brief: one treatise, n. 54, On the signs of the diseases of the eye, describes the eye diseases according to the anatomical structure in which they appear, whereas the second text, n. 35, On the anatomy of the eye, seems not to be a genuine Galenic work.8 The title and the structure of the fragment found in the 14th century Venetian Marc. gr. 276 at first sight seems to meet all the criteria of the lost text,9 although the style is a bit too compressed for Galen. The fragment reads: + Galen’s On the Diagnosis of the Diseases of the Eye: + The eyes, as all things of this kind, are affected by diseases according to their nature. Their nature is as follows: two tunics enclose a twofold liquid structure. One of the liquids is called «ice-like», and it is like this according to its colour and consistency, the other one «glass-like», for it resembles completely liquid glass. The «ice-like» is carried within the «glass-like» like a ball. The inner tunic resembles a grape, hence it has the name «grape-like». + Although its title indicates a diagnostic work, the fragment starts off with anatomy, which is not unprecedented in ophthalmological texts10 (but not attested in any other diagnostic writing). The reason for this was purely practical. Medical treatises were commonly arranged in a simple head to foot order. That is to say, the diseases of the head were covered at the beginning of the book, while the diseases of the feet were described towards the end. Usually, this system was straightforward and easy to apply, as the location of the diseases was mostly obvious. In the case of eye diseases, however, the situation was more complicated. The anatomy of the eye itself was a contested issue, and as a result there was no straightforward order in the sense of a capite ad calcem. As with other diagnostic topics, authors chose to present their subject in a structural sequence, for instance proceeding from the outside of the eye, the conjunctiva, towards the innermost. Thus, it became necessary to outline the anatomical theory first, in order to make the author’s specialist knowledge accessible to the reader.11 Therefore, the literary form of our fragment makes sense, and it is quite likely that the lost Galenic tract also contained a brief chapter on anatomy. Another issue, however, argues strongly against Galenic authorship: the content of the anatomical passage is not consistent with what we know about Galen’s understanding of anatomy. The discrepancy lies in the number of tunics and fluids that form the eye. The two major Galenic works on the anatomy of the human body, anatomicae administrationes and de usu partium have a three liquid/four tunic system,12 whereas the fragment only mentions two of these structures each. Most of the Greek texts which have come down to us contain an almost identical understanding of the anatomy of the eye: it consists of three liquids and several tunics and can be divided into anterior and posterior chamber. Some of the descriptions give us an idealized impression of the eye as a ball-like shape with liquids in the centre and tunics enclosing them like an onion. The lens is situated in the middle of the eye, and it was believed to be the organ of perception.13 Some of the accounts go into further detail and describe even very subtle structures which are macroscopically almost invisible. Yet, even within any one treatise the terminology is sometimes not entirely clear – is a structure a tunic or a membrane and do tunics in the anterior and posterior chamber form a unit or are they separate? And is the retina a tunic although it is part of the optic nerve which is an extension of the brain? Throughout the medical literature there is, despite all similarities, no consistent terminology, and often even colloquial expressions like ‘the black of the eye’ invade the text and make it unclear whether an author meant the iris or the pupil. As many sources are lost, it is very difficult for us to reconstruct the origins of this understanding. We have three brief historical accounts on the history of the anatomy of the eye, one in Greek, in the pseudogalenic introductio14 and two in Arabic, both in ophthalmological works of unain ibn Isḥāq15 describing and rationalizing different approaches; it is not clear whether they built their assumptions on primary sources (i.e. a text on the anatomy of the eye) or on a secondary source that is today lost, for instance yet another historical analysis. All three texts mention an anatomical system resembling the one found in our fragment, namely two liquids, lens and vitreous body, and two tunics, of which choiroid/iris form the inner layer and the sclera/cornea the outer one, and one of the texts, the introductio, attributes the system to Hippocrates.16 The key difference from Galen’s system is the absence of the retina – although it is not entirely clear whether it was unknown to the author of our fragment, or whether it was known, but not regarded as a tunic.17 Moreover, the absence of another anatomical detail, the aqueous humour, a liquid situated between the lens and the cornea, means that the anatomical understanding underlying this fragment is out of date and superseded by Galen and his contemporaries.18 Whether or not our fragment is, in some way, Hippocratic is impossible to decide; the reference in the introductio certainly suggests that it is, but of course it could be the case that two medical authors independently postulated a two tunic/two liquid system. The fact that the fragment is crossed out probably means that the scribe realized it was not Galenic (which requires a considerable amount of specialist knowledge), and therefore not worth copying. I would like to conclude with an observation that is even more intriguing from a historical point of view. From the present fragment we can see that a primary source, an original work, with an outdated anatomical understanding was still extant as late as the fourteenth century, and one is wondering how it happened to have invaded a collection of Galenic works. That a text was falsely attributed to an author is not uncommon; this could occur either by mistake or in order to increase the value of a manuscript. But our fragment is odd enough to have been crossed out, and apart from its title it is neither in style nor in content in any way close to Galen. Maybe there were more diverse texts on the eye circulating that evaded the predominance of Galenic thought than previously believed, and it could very well have been the case that both the author of the introductio and unain were aware of primary sources like our fragment when they compiled their historical accounts of the anatomy of the eye.