18th c. understanding?

[D B Campbell]

A major difference between those times and today is that the educated gentleman of the 18th century would have been fluent in Latin, and probably Greek as well, practically from the time he first learned to read.

In the seventeenth and eighteenth centuries, it was common for Greek works to be translated into Latin, to reach a wider readership.

In the 18th century a military man of almost any nation could quote you Caesar or Arrian or Vegetius by the hour.

Agreed -- with the above-noted proviso, that the texts available in the eighteenth century were often not as authoritative as the ones we take for granted today.

See above for Caesar and Vegetius. Arrian is another interesting one. The History of Alexander (Anabasis Alexandrou) was known quite early on, particularly in French translations. And the simplicity of the manuscript tradition (all versions go back to a single twelfth/thirteenth century exemplar) means that the text has always been quite sound.

However, for the military man, Arrian's Tactics (Ars Tactica) is a different matter. Although the manuscript tradition is reasonably straightforward -- our knowledge of the main tactical writers goes back to a single tenth century exemplar which was then copied in various versions -- early editions were often inferior because they failed to give the exemplar its due weight, and often preferred variant readings. (Even the well-known Köchly-Rüstow edition (1855) fails on this score.) In addition, a problem peculiar to Arrian's Tactics is that the extra Roman section (not found in the other tactical writers) was routinely omitted until the 1960s.

Our educated gentleman of 1760 may have known about Guischardt's Mémoires militaires sur les Grecs et les Romains (published in that same year), but nobody nowadays would use that volume. Better editions of Arrian and Asklepiodotos are available (though we are still waiting for a critical edition of Aelian).