If these mythographer-historians were uncritical with regard to the basic nature of their material (and were rarely worried by the fabulous element in myth), they were by no means uncritical regarding the historical implausibilities which can arise from deficiencies in chronology and internal inconsistencies within the mythical narratives. With regard to chronology, they continued the enterprise begun in the Hesiodic Catalogueby refining and further developing the heroic genealogies, and trying to improve the synchronisms between families. In other respects, these authors could also be seen as heirs to the epic poets in the Homeric tradition. Many composed extensive narratives and most undertook to collect together the myths associated with the various cycles, and where necessary reconcile or choose between conflicting versions, and iron out contradictions to establish a convincing narrative.

The works of the two mythographer-historians explicitly cited by Apollodorus were complementary in character. Acousilaos of Argos probably wrote at the end of the sixth century, as a contemporary of Hecataios (although some would place him somewhat later). He aimed to provide a systematic account of the entire mythical tradition, rigorously organized on a genealogical basis. The material was ordered in much the same way as in the Library, although on a far larger scale; as in the Library, most of the figures in heroic mythology were assigned to one or other of a small number of important families, and the history of each of these families was narrated separately from beginning to end. In this regard, Acousilaos used the Hesiodic Catalogueas his model, developing or modifying the genealogies as he thought necessary. As might be expected in an author of Argive birth, Acousilaos seems to have stressed the centrality of the Argive traditions in his account of Peloponnesian mythology.

Pherecydes of Athens composed his history somewhat later, probably in the first half of the fifth century. His writings were more copious than those of Acousilaos, and it seems that his prime concern was to gather together as complete a collection as possible of the traditional myths. He was correspondingly less interested in genealogical matters, and the organization of his works would necessarily have been much looser in view of the quantity of diverse material collected within them. Indeed, the principles that he followed in this respect are not at all clear from the surviving evidence. He is the mythographer-historian most frequently quoted by the scholiasts, who (like Apollodorus) clearly valued him for his copious records of early myth, narrated in a pleasantly ingenuous style. Since the narratives preserved from the works of later mythographers are generally so lacking in charm, it is a particular shame that the works of this mythographical Herodotus should have been lost. Sometimes we detect something of their flavour in the summaries in the Library.

Another mythographer-historian should also be mentioned who was certainly consulted by the author of the Libraryalthough he is not cited by name. Hellanicos of Lesbos, who wrote in the second half of the fifth century, was closer in spirit to Acousilaos than to Pherecydes, for he was important above all for his contribution to the fine-tuning of the genealogical system. He was less interested in the narration of myth, and the passages preserved by the scholiasts suggest that his writings were marked by a certain dryness and a rationalizing tendency rarely in evidence in the works of his predecessors. He was nevertheless an important authority on certain aspects of mythical history, notably the Trojan War.

In the main, and allowing for a few important contributions from tragedy and later sources, the Librarysummarizes the canon of myth as it was defined in the works of these mythographer-historians and in early epic poetry; and for much of its organization, the Libraryrelies on the genealogical system developed in the Hesiodic epics and further refined by the early prose mythographers. The author’s dependence on epic (and other poetic sources) would often have been indirect. Most of the stories from early epic would have been summarized in prose in the works of the mythographer-historians, and collections of summaries of epic and tragic plots became widely available in the Hellenistic era. These would have provided our author with the models for his own summaries, and would usually have served as his immediate sources. Indeed, it can be assumed that he would rarely have worked directly from a poetic source. He seems, however, to have had a thorough knowledge of the Hesiodic Catalogue, and, as would be expected, of the Homeric epics. Although the theogony at the beginning of the Libraryis largely based on Hesiod’s Theogony, the author preferred to follow other sources on some significant points (as is remarked in the Explanatory Notes).

In many parts of the Library, the narrative can be regarded as being, in all essentials, a brief epitome of relevant sections from the works of the mythographer-historians (and much of its interest and value could be said to have derived from that). Pherecydes seems to have served as the author’s main model, although he also followed other historians when they were the main authorities on a particular area, as was Acousilaos on Argive myth, or Hellanicos on the myths connected with Troy. Not all scholars have agreed, however, that the author of the Librarydrew his material directly from these early prose sources, even where we can be certain that it was ultimately derived from them. For he had all the resources of Hellenistic mythography available to him, including handbooks which would have contained summaries of material from such writers. In his influential study, Carl Robert argued that the Libraryis little more than a precis of an earlier handbook by a Hellenistic author; and amongst German scholars at least, such a view came to be widely accepted in the early part of this century. Because we have to rely on fragments for our knowledge of most of the Library’searlier sources, this is by no means an easy question. Nevertheless, the most detailed examination of the evidence hitherto (in the article by M. Van der Valk cited in the Select Bibliography) gives reason to suppose that the author referred directly to the writings of the mythographer-historians when he was following one of them as his main source in a particular part of the work.

The author of the Libraryalso drew on a variety of other sources. Besides epic poetry, his earlier sources would naturally have included lyric and elegiac poetry, and the ‘tragic Muse’, as was stated in the little poem attributed to him. The great Attic dramatists of the fifth century generally relied on heroic mythology for their plots, in particular the stories associated with the Argive and Theban royal families and the Trojan War. But they adapted the traditional stories with considerable freedom, whether for dramatic effect or to develop a moral of their own, and were thus responsible for some striking innovations which had a marked influence on the development of the tradition. In certain cases the tragedians contributed the canonic version of a particular story, while in many others they provided appealing variants. Both aspects of this influence are evident in the Library. Thus the account of the life of Oedipus is in the main a summary of Sophocles’ version in his Oedipus plays, for this became the canonic version, largely displacing the very different accounts in early epic; but the plot of a play by Euripides on Alcmaion (p. 114) is included merely as an interesting variant, in a supplement to the main account based on the earlier tradition.

To proceed to the Hellenistic poets, Apollodorus based his account of the voyage of the Argonauts on the Argonauticaof Apollonius of Rhodes, a relatively late epic written in the third century BC. As was common in that age, Apollonius was a scholar as well as a poet, and he made extensive use of the early sources in composing his poem. For certain stories, however, such as the murder of Apsyrtos (p. 54), the author of the Libraryprefers to report a more primitive version than was found acceptable in this late epic. Otherwise his interests diverge from those of the Hellenistic poets, who tended to concern themselves with the more recondite aspects of the tradition, and he draws on them only for the occasional learned variant. As to the mythographical literature of this period, it was observed above that he would have made use of the resources that it provided. It is likely that some of his narratives are based on Hellenistic summaries of epic or tragic plots; and mythical variants, collections of references, and alternative genealogies may often have been drawn from Hellenistic handbooks. Apollodorus would have valued such literature as a source of instant erudition, but there is nothing to indicate that the Libraryis marked in any deeper sense by Hellenistic scholarship, and the author had no interest whatever in the rationalistic interpretations favoured by many Hellenistic scholars.