a) An act in preparation for which the main act takes place; as,—­

    priusquam dimicarent, foedus ictum est, i.e. in anticipation of the
    fight, a treaty was struck.

  By an extension of this usage, the Subjunctive is sometimes used of
  general truths, where the anticipatory notion has faded out; as,—­

    tempestas minatur antequam surgat, the tempest threatens before it
    rises.

  b) An act anticipated and forestalled; as,—­

    priusquam telum adici posset, omnis acies terga vertit, before a spear
    could be hurled, the whole army fled.

  c) An act anticipated and deprecated; as,—­

    animum omittunt priusquam loco demigrent, they die rather than quit
    their post.

2.  After historical tenses the Imperfect Subjunctive is used, especially by some writers, where the notion of anticipation has practically vanished; as,—­

    sol antequam se abderet fugientem vidit Antonium, the sun before it
    set saw Antony fleeing.

Clauses introduced by Dum, Donec, Quoad.

293. 1.  Dum, while, regularly takes the Indicative of the Historical Present; as,—­

    Alexander, dum inter primores pugnat, sagitta ictus est, Alexander,
    while he was fighting in the van, was struck by an arrow;

    dum haec geruntur, in fines Venellorum pervenit, while these things
    were being done, he arrived in the territory of the Venelli.

II.  Dum, donec, and quoad, as long as, take the Indicative; as,—­

    dum anima est, spes est, as long as there is life, there is hope;

    Lacedaemoniorum gens fortis fuit, dum Lycurgi leges vigebant, the race
    of the Lacedaemonians was powerful, as long as the laws of Lycurgus
    were in force;

    Cato, quoad vixit, virtutum laude crevit, Cato, at long as he lived,
    increased in the fame of his virtues.

III.  Dum, donec, and quoad, until, take:—­

1.  The Indicative, to denote an actual event; as,—­

    donec rediit, fuit silentium, there was silence till he came;

    ferrum in corpore retinuit, quoad renuntiatum est Boeotios vicisse, he
    kept the iron in his body until word was brought that the Boeotians had
    conquered.

  a.  In Livy and subsequent historians dum and donec in this sense often
  take the Subjunctive instead of the Indicative; as,—­

    trepidationis aliquantum edebant donec timor quietem fecisset, they
    showed some trepidation, until fear produced quiet.

2.  The Subjunctive, to denote anticipation or expectancy; as,—­

    exspectavit Caesar dum naves convenirent, Caesar waited for the ships
    to assemble;