Temporal Clauses introduced by Cum.

A. Cum REFERRING TO THE PAST.

288. 1.  Cum, when referring to the past, takes,—­

A. The Indicative (Imperfect, Historical Perfect, or Pluperfect) to denote the point of time at which something occurs.

B. The Subjunctive (Imperfect or Pluperfect) to denote the situation or circumstances under which something occurs.

Examples:—­

  INDICATIVE.

    an tum eras consul, cum in Palatio mea domus ardebat, or were you
    consul at the time when my house burned up on the Palatine?

    credo tum cum Sicilia florebat opibus et copiis magna artificia fuisse
    in ea insula, I believe that at the time when Sicily was powerful in
    riches and resources there were great crafts in that island;

    eo tempore paruit cum parere necesse erat, he obeyed at the time when
    it was necessary to obey;

    illo die, cum est lata lex de me, on that day when the law concerning
    me was passed.

  SUBJUNCTIVE.

    Lysander cum vellet Lycurgi leges commutare, prohibitus est, when
    Lysander desired to change the laws of Lycurgus, he was prevented;

    Pythagoras cum in geometria quiddam novi invenisset, Musis bovem
    immolasse dicitur, when Pythagoras had discovered something new in
    geometry, he is said to have sacrificed an ox to the Muses.

a.  Note that the Indicative is much less frequent in such clauses than the Subjunctive, and is regularly confined to those cases where the main clause has tum, eo die, eo anno, eo tempore or some similar correlative of the cum.  Sometimes it depends entirely upon the point of view of the writer whether he shall employ the Indicative or Subjunctive.

2.  Cum Inversum.  When the logical order of the clauses is inverted, we find cum with the Perfect Indicative or Historical Present, in the sense of when, when suddenly.  The main clause in such cases often has jam, vix, aegre, nondum; as,—­

jam Galli ex oppido fugere apparabant, cum matres familiae repente procurrerunt, the Gauls were already preparing to flee, when suddenly the matrons rushed forth (logically, the matrons rushed forth as the Gauls were preparing to flee);

    Treviri Labienum adoriri parabant, cum duas legiones venisse
    cognoscunt, the Treviri were preparing to attack, when (suddenly) they
    learned that two legions had arrived.

3.  To denote a recurring action in the past, cum is followed by the Indicative, particularly of the Pluperfect (compare Sec. 287, 2; 302, 3); as,—­

    cum ad aliquod oppidum venerat, eadem lectica ad cubiculum deferebatur,
    whenever he had arrived at some town, he was (always) carried in the
    same litter to his room;