Help with some grammar in Euclid's Elements

Latin Learning Latin
1

I’m reading a Latin translation of Euclid, and I came across the following version of definition 9 (Book I):

Quando autem quae angulum continent rectae lineae fuerint, rectilineus angulus appellatur.

My question is how is “fuerint” functioning in the sentence? Based on its form, I’m guessing it’s 3rd person plural perfect active subjunctive, but I can’t convince myself that this works. Any insights would be appreciated.

2

Salve paulus123

Yes, perf act sub

When, however, what [lines] contain the angle > would have been > straight lines, the angle is called rectilinear

3

Where did you find Latin version of Elements? Is it available on the Internet?

4

I didn’t look for it, paulus123, but there will be many out there.
Non quaesivi, sed multos ibi invenies.

5

exempli gratiâ: http://www.google.ie/search?hl=en&q=euclidis+elementa&btnG=Search&meta=

6

Thanks for the feedback. I quess to my ear using the subjunctive sounds a little to tenative for a definition. How would you classify this use of the subjunctive? Is this a style commonly used for definitions in Latin?

The downloadable version of the book can be found at

http://books.google.com/books?id=sioVAAAAQAAJ&pg=PA325&dq=intitle:Euclidis+intitle:Elementorum+intitle:libri+intitle:priores+intitle:sex&lr=&as_brr=1&as_pt=ALLTYPES

Thanks again for your comments

7

Vide ità:



You have indeed a dependent clause referring to a condition that might pertain (so subjunctive in Latin). Were the condition to pertain (or have pertained,—so past tense), then as a consequence, “it is a rectilinear angle”. Convoluted, I know, but I’m trying to justify the writer’s thinking. In English, you tend to say “it will be a rectilinear angle”, which is no less strange, I suggest, in referring to the potentiality of a general truth.

Dependentem clausulam quidem habes, ut conditionem quae pertineat demonstrat (ideò subjunctivo modo latiné). Si conditio pertinuisset, tunc ab eam causam, est angulus rectilineus. Tortuosum, scio, sed mentem scriptoris excusare conor. Anglicè paenè dicas “it will be a rectilinear angle” , quod non minùs externum est, suggero, veri potentiam generalis in demonstrando.