On sources

Jeb McLeish sent me a link to this rather fascinating monograph, which translates Isidore of Seville’s medical section of the Etymologiae (c632), with an extensive foreword by the translator, William D. Sharpe. I recommend the introduction as a summary of the state of knowledge between the fall of the Roman Empire and the rise of the medieval renaissance.

Sharpe writes about the difficulty of tracing influence:

Evaluation and identification of the sources used by an ancient encyclopedist in his compilations are always uncertain, lacking citation by name at a time when neither copyright law nor scholarly convention so required. It is never safe and may be foolhardy to presume that verbal similarity between author “A” who happens to have written a generation earlier than author “B” implies that author “A” is beholden, directly or indirectly, to author “B” for his ideas or their expression, or that an influence of any kind can be predicated. There has always been a common body of scholarly and scientific information to which anyone has or can gain access, and an apparently original or prior conclusion or statement may stem from a common source long since lost, from identical or similar sources, or from parallel but independent origins. Influence may exist, but its proof is rigorous and requires much more than opportunity. This problem is complicated by the loss of many important works once popular, by the lack of scientific critical texts for many early medieval writers and by the uncertainty induced by the recollection that the accepted reading of a given text fifteen centuries ago need not have been that now taken to be correct. Few libraries, ancient or modern, are completely catalogued and fewer still of such catalogues have survived from medieval times to us, so that any opinion on the acquisition and interchange of books, whether by individuals or by institutions, rests to a large extent on fragmentary evidence and upon conjecture. [p21]

Sharpe, William D. 1964. Isidore of Seville: The Medical Writings. An English Translation with an Introduction and Commentary. Transactions of the American Philosophical Society 54 (2):1-75.