Already we have treated of a number of Arabic works of occult science which are extant in Latin translations, or have mentioned men, important in the history of medieval science like Constantinus Africanus or Adelard of Bath, whose works were either largely or partly translations. In future chapters we shall have occasion to mention other men and works of the same sort. We have already seen, too, that translations from the Greek were being made all through the early middle ages and in the tenth century; and we shall see this continue in the twelfth and thirteenth centuries especially in connection with Galen, Aristotle, and Ptolemy. We have also seen reasons for suspecting that the Latin versions of certain works were older than the so-called Greek originals, that works were sometimes translated from Arabic into Greek as well as from Greek into Arabic, and that there probably never were any Arabic originals for some so-called translations from the Arabic which are extant only in Latin. All this is not yet to mention versions from Hebrew and Syriac or in French, Spanish, and Anglo-Saxon. We have seen also in general how important and influential in the history of medieval learning was the work of the translator, and yet how complicated and difficult to follow. Many names of translators are mentioned in the medieval manuscripts: some, for instance, who will not be treated of in the present chapter are: from the Greek, Aristippus of Sicily, Bartholomew of Messina, Burgundio of Pisa, Eugenius admiral of Sicily, Grumerus of Piacenza, Nicolaus of Reggio, Stephen of Messina, and William of Moerbeke; from the Arabic, Egidius de Tebaldis of Parma, Arnold of Barcelona, Blasius Armegandus or Ermengardus of Montpellier, Marcus of Toledo, the canon Salio of Padua, John Lodoycus Tetrapharmacus, Philip of Spain, Philip of Tripoli, Roger of Parma, Ferragius, and so on. But not all such names of translators can be correctly placed and dated, and many translations remain anonymous in the manuscripts. Into this vast and difficult field Jourdain’s work on the medieval translations of Aristotle made but an entrance, and that one which now needs amendment, and even such extensive bibliographical investigations as those of Steinschneider have only made rough charts of portions. Some detailed monographs on single translators[159] and the like topics have been written, but many more will be required before we shall have a satisfactory general orientation. [Sidenote: Plan of this chapter.]