The Latin had no article, as the Greek has no indefinite article. Not even in the modern Greek has the indefinite article of the Teutonic and Roman tounges developed, though occasionally εις or τις is used with little more force than the English a (an). Even in the New Testament we see traces of this use of εις in Mat 8:19 where εις γραμματευς is equivalent to “a” in English
και προσελθων εις γραμματευς ειπεν αυτω διδασκαλε ακολουθησω σοι οπου εαν απερχη
and a certain scribe having come, said to him, `Teacher, I will follow thee wherever thou mayest go
In fact, the English one, Scotch ane, French un, German ein is simply the cardinal “one” adapted to this very usage. Children often say: “That was one funny man.” So likewise τις is used where “certain” is rather to emphatic in English as in Luke 10:25.
και ιδου νομικος τις ανεστη εκπειραζων αυτον και λεγων διδασκαλε τι ποιησας ζωην αιωνιον κληρονομησω
And lo, a certain lawyer stood up, trying him, and saying, `Teacher, what having done, life age-during shall I inherit?