BMCR 2003.05.14

Eratosthenes von Kyrene. Studien zur hellenistischen Kultur- und Wissenschaftsgeschichte

, Eratosthenes von Kyrene: Studien zur hellenistischen Kultur- und Wissenschaftsgeschichte. Münchener Beiträge zur Papyrusforschung und antiken Rechtsgeschichte, 92. Heft. München: C.H. Beck, 2002. x, 412 pages. ISBN 3406489761. EUR 88.00.

At the time when the new library at Alexandria opened its gates, the first comprehensive monograph on the head librarian of the old library at Alexandria between 246 and c.196 BC, Eratosthenes of Cyrene, came out. This rich book is the somewhat revised version of Geus’ Habilitationsschrift (post-doctoral thesis) at Bamberg University. Due to the universal interests of this Alexandrian scholar that comprised such diverse fields as philosophy, poetry, grammar, musical theory, history, chronography, mathematics, astronomy, and geography, nobody has tried to deal with life and the complete oeuvre of Eratosthenes in one book before. Geus’ ambitious aim is to shape a full picture of this outstanding Hellenistic scholar and his “intellectual profile”, including his significance for Hellenistic cultural history. He succeeds well and has produced a fine book, full of references, arguments and engaging details.

The study of Eratosthenes is made difficult not only by the diversity of his interests, but also by the lack of a reliable edition of his fragments. The only collection that made an effort to include fragments from all fields, is the completely outdated Bernhardy of 1822 (repr. 1968). Other old editions give parts of the fragments: Berger the geographical, Strecker those on the old comedy, Powell the poetic, Jacoby the chronographical and some miscellaneous.1 Admittedly, to work out a new collection is a difficult task, especially as the ascription of several fragments to particular works remains contested and much of the relevant ancient literature on astronomy or mathematics is not properly edited. Geus did not attempt to edit a new collection but hopes that his book would substitute for a new edition of the fragments (p. 2 n. 3). I am afraid that this will not prove possible. Geus has collected the fragments known to him and he gives their reference in a paragraph at the beginning of each chapter before treating them in his text and footnotes. For the most important fragments he gives a German translation, which might not be immediately helpful to English readers but is generally welcome as it enables the non-classicist to engage in the discussion. Instead of using fragment numbers — which would be hazardous without an authoritative collection — Geus quotes author, work, and passage where the respective fragment is to be found. To the reader and user of his book this proves arduous, because for checking these often rare references one needs to have an excellent library at hand. I do not want to diminish Geus’ solid treatment of the evidence, but to emphasize that a new edition would be very helpful indeed.

The book contains 12 chapters, bibliography and two indices (that of passages includes references by fragment numbers to the diverse collections; the other one refers to names and subjects). Several line drawings illustrate difficult details. Chapters IV-XI deal with Eratosthenes’ works according to his fields of interest. Each of these chapters is prefaced by the evidence, giving the references — where possible pointing to the relevant collections of Eratosthenes’ fragments — supplemented by new fragments, mentioning those which have been dismissed, and the relevant literature.

After an introduction on aim, method, and a short bibliographic report, the second chapter treats Eratosthenes’ biographical data. Geus carefully discusses the ancient evidence, taking the Suda article as generally reliable. He does not, however, agree with Eratosthenes’ age given by the Suda and prefers the 82 years of Ps.-Lucian, macr. 27. Geus goes on to discuss a wealth of biographical details such as assumptions about Eratosthenes’ teachers, the background for his call to Alexandria, his nicknames, his death, his pupils.

The third chapter considers the catalogue of his writings and their relative chronology. Geus neither follows the inflation of titles once ascribed to Eratosthenes nor Bernhardy’s tendency to reduce their number to about a dozen.

The fourth chapter treats philosophical dialogues. Geus holds that most of the fragments with biographical details stem from these dialogues, using a very pointed style and a wealth of exempla. The only fragment from a work with the title Arsinoe is the starting point of a discussion about biography in antiquity, concluding that this fragment represents part of a dialogue rather than a biography. The same conclusion is drawn for Ariston and Πρὸς Βάτωνα. A biographical detail on the philosopher Pyrrhon of Elis belongs to a dialogue Περὶ πλούτου καὶ πενίας, not to be identified with the dialogue Περὶ πλούτου. There is no fragment from Περὶ ἀλυπίας, but it is mentioned by the Suda article on Eratosthenes, which prompts Geus to consider it one of the best known dialogues. The dialogue Περὶ ἀγαθῶν καὶ κακῶν apparently discussed different ways to die illustrated by historical-biographical exempla. Geus argues that the statement one should not distinguish between Greeks and Barbarians but between virtuous and bad people was probably not only found in the Geographika, but also in this dialogue. Eratosthenes’ treatise Περὶ τῶν κατὰ φιλοσοφίαν αἱρέσεων could be the first doxographical history of philosophy. Geus summarizes Eratosthenes’ philosophical dialogues by pointing out that he after all was no philosopher, but a philologist.

The next chapter is dedicated to the poet. There are several fragments of poems: Hermes, the most famous, the Erigone, Hesiod or Anterinys, Διόνυσος κεχηνώς, and a bridal song. Geus attempts to reconstruct their contents, looks for a common aspect and evaluates them within Eratosthenes’ oeuvre. The poem Hermes is considered by Geus rather scientific in content, since many passages are quoted in scientific works, with myth and science melted together. Several scientific theories seem to have been already dated when he wrote the poem but were later improved in his Geographika. Geus detects a strong Platonic influence and argues that most of these poems were written before Eratosthenes left Athens. The dedicatory epigram that goes with a letter to Ptolemy III is the only complete poem of Eratosthenes and again deals with geometrical problems.

The sixth chapter treats the Platonist. Geus argues that all fragments with mathematical, scientific and musical content stem from the Platonikos (logos), not a dialogue but a work on Plato of protreptic tendency. Eratosthenes defined important terms from the fields of mathematics, musical theory and metaphysics to comment on difficult passages of the Corpus Platonicum, including the Ps.-Platonic Epinomis. Geus holds that there was more Platonic thought in Eratosthenes than is generally believed and that Eratosthenes tried to identify a crucial momentum for the interpretation of Plato which he saw in the theory of proportions. This chapter is full of demanding topics, and Geus succeeds well in illuminating a number of intricate problems. It is in Eratosthenes’ Platonikos that we find a version of the Delian problem: the duplication of the cube. Eratosthenes’ mathematical solution is based on an appliance that could be a prototype of the mesolabos, a mathematical instrument for finding mean proportional lines. The letter to Ptolemy III, written a short time after the Platonikos, describes the votive offering of the instrument later called mesolabos. Geus argues that both the letter and the accompanying dedicatory epigram mentioned above are authentic and thus the only Eratosthenic works preserved in their entirety.

The seventh chapter is concerned with the astronomer. Περὶ τῆς ὀκταετηρίδος deals with the problem of the difference between the sun and the moon year. Eratosthenes was concerned in particular with the problem that the festival of Isis moved through the whole sun year. Geus combines this bit of information with the famous Canopus decree of Ptolemy III that includes the proposal to add one day every four years to keep the festivals at the right time of the year and assumes the advice of Eratosthenes behind this royal reform. Eratosthenes’ rather popular work on constellations ( Ἀστρονομία ἢ Καταστηριγμοί), comprising both a catalogue of stars and constellations and the myths connected with these, is irretrievably lost and can only be reconstructed via an adaptation from the second century AD that was made to serve as a commentary to Aratus’ Phainomena, which itself has to be retrieved from several authors and scholia. This difficult source material is used by Geus to get an idea of Eratosthenes’ original intentions.

The most important astronomical work of Eratosthenes is his Περὶ τῆς ἀναμετρήσεως τῆς γῆς (On the measurement of the earth) in which, combining astronomy and geography, he treated not only the circumference of the earth but also the tropics, the polar circles, the polar regions, size and distance of sun and moon, partial and total eclipses of sun and moon, the different lengths of daylight according to latitudes and seasons, and the obliquity of the ecliptic. Geus also ascribes the calculation of mountain tops and observations on winds and a wind rose of eight unequally distributed points to this work. After recounting the history of attempts to estimate the circumference of the earth, Geus gives a clear reconstruction of how Eratosthenes achieved his number. He points out that it is hard to tell how precise Eratosthenes’ result was as the exact length of the stadium used is unknown, but the achievement in applying geometrical propositions is most impressive.

The eighth chapter treats the geographer. Geus states that it is difficult to divide the fragments between Eratosthenes’ work on the measurement of the earth and his Geographika, and so he does not go into details for every single fragment in this chapter (p. 260 n. 1). Nevertheless, Geus gives many insights into this famous work of Eratosthenes who is said to have started the genre of scientific geography. In fact, however, he collected this wealth of information — not only geographical in the narrow sense, but ethnographical, too — in an antiquarian manner and synthesized it. Geus emphasizes that Eratosthenes was overall interested in cartography and developed what was originally a περίοδος γῆς into a structured drawing and description based on measurement, divisions and locations. The first book of the Geographika gave the fundamentals of geography and its history, the second probably tried to establish the need for mathematics and physics, and the third was dedicated to the design and description of the map of the world. Geus discusses the content of each of these books, engaging with details and long established opinions and, where necessary, modifying or refuting them.

The ninth chapter is concerned with the philologist. Apparently, it was not only Eratosthenes’ self-description as being a philologos, but he indeed seems to have been very popular for his grammatical works: there are about one hundred fragments that have come down to us. Περὶ τῆς ἀρχαίας κωμῳδίας, the best known of his philological works, was not a continuous commentary on the old comedy but included observations concerning linguistics and content even beyond old comedy, in particular lexicological explanations. The Architektonikos was probably a collection of glosses or an onomasticon; the Skeuographikos gave descriptions of tools or utensils; he commented on Homer in his Εἰς τὸν ἐν τῇ Ἰλ[ιάδι and on further grammatical problems in his Grammatika. Geus summarizes Eratosthenes’ achievements in this field in saying that he was learned and critical, but not an innovator.

The tenth chapter is dedicated to the chronographer. Eratosthenes is commonly thought to have started scientific chronography, a claim that is challenged by Geus, who sees Eratosthenes as less interested in setting up a chronology than in collecting facts as a philologist interested in chronological questions.2 Ancient tradition does not seem to have valued his chronographical works as much as his work in other fields. One possible chronographical work represents the list of the kings of Egyptian Thebes, which Syncellus considered a translation from the Egyptian records by Eratosthenes following an order of the king. Geus maintains that the list as we have it today might go back to Eratosthenes’ translation but that we cannot distinguish between his material and later elaborations. Therefore he refrains from considering it further, but accepts Syncellus’ statement (cf. p. 57). There are, however, good arguments to assume that Eratosthenes ignored the Egyptian tradition altogether as he does not even show knowledge of Manetho’s Egyptian history written in Greek.3 Why should he have cared about Egyptian records from a temple? Syncellus’ assertion that Eratosthenes translated the lists of the priests at Diospolis sounds like one of the favourite claims of authority used to disguise an unidentified source or a falsification.4

The other two chronographical works Περὶ χρονογραφιῶν and the Olympionikai are not easy to reconstruct. Many fragments can be ascribed to the one or the other, depending on assumptions about their respective character. Geus claims that the work on chronographies was rather a critique of existing chronographical literature than a systematic account of earlier times, only giving the rough outline as we have it in Clement of Alexandria (FGrHist 241 F1a). He thus considers it impossible to reconstruct Eratosthenes’ complete chronographical system. Geus doubts the common assumption that Apollodoros depended closely on Eratosthenes. Not leaving too many fragments to the Περὶ χρονογραφιῶν, Geus considers the Olympionikai Eratosthenes’ main chronographical work and reconstructs it as a literary work on the Olympic games drawn from literary material, in any case much different from a more or less bare list of Olympic victors.

I have reservations about diminishing the value of On chronographies compared to the Olympionikai, and wish to go into one detail. Geus claims that Eratosthenes’ calculation of Lycurgus’ date as given by Plutarch (Lyc. 1, 3) was once to be found in the Olympionikai and not in On chronographies. The Plutarch passage, however, seems to have been made up from diverse sources, among them Eratosthenes’ On chronographies, if we take serious the outline handed down to us by Clement (FGrHist 241 F1a). This fragment clearly shows that Eratosthenes dated Lycurgus at a distance of 108 years before the year preceding the first Olympic games. Moreover, Plutarch’s remark that Lycurgus was dated according to the Spartan king list fits better into the broader context of On chronographies.

Chapter eleven deals with the historian and Geus argues that the history of the Galatians ( Γαλατικά) could very well be a late work of Eratosthenes.

The final chapter discusses the significance of Eratosthenes for ancient intellectual history. Geus asks about the cultural exchange between Greece and Egypt and summarizes that very little Egyptian influence on Eratosthenes can be ascertained and that he surely was no focal point in the process of assimilation between Egyptian and Greek culture. Eratosthenes cannot be tied to a philosophical school, but certainly he was most interested in Platonic thought. He had a high reputation as a mathematician, though he apparently was better in applied than in pure mathematics. Generally, one gets the impression that his strength lay in systematizing and historicizing a number of fields such as chronography, grammar, geography and astronomy. Geus sees the intellectual development of Eratosthenes as a continuous advance from the poet and philosopher admiring Plato to the mathematical astronomer and geographer to finally the philologist using historical methods.

Geus has worked through a wealth of sources and literature and challenged long established interpretations and widely accepted views. Obviously, one can disagree with one or the other of his interpretations. His scholarly industry has produced a rich book with masses of learned footnotes and an effort to cover every possible turn in the argument. This important book on an outstanding Hellenistic scholar serves well to all further study of Eratosthenes.


1. G. Bernhardy, Eratosthenica, Berlin 1822; H. Berger, Die geographischen Fragmente des Eratosthenes, Leipzig 1880; J.U. Powell, Collectanea Alexandrina, Oxford 1925, 58-68 (with H. Lloyd-Jones, P. Parsons, Supplementum Hellenisticum, Berlin 1983, Nos. 397-9); C. Strecker, De Lycophrone Euphronio Eratosthene comicorum interpretibus, Diss. Greifswald 1884; F. Jacoby, FGrHist 241.

2. The same challenge, with different arguments, comes from A. Grafton, Tradition and Technique in Historical Chronology. In: Ancient History and the Antiquarian. Essays in Memory of Arnaldo Momigliano, ed. by M.H. Crawford, C.R. Ligota, London: Warburg Institute 1995, 15-31, at 21-6.

3. J. Blomquist, Alexandrian Science: The Case of Eratosthenes. In: Ethnicity in Hellenistic Egypt, ed. by P. Bilde et al., Aarhus 1992, 53-73, at 64.

4. cf. Grafton (as above) 23-4.