[304]. 1. Here we regularly have the Subjunctive in both Protasis and Apodosis, the Imperfect referring to present time, and the Pluperfect referring to past; as,—
sī amīcī meī adessent, opis nōn indigērem, if my friends were here, I should not lack assistance;
sī hōc dīxissēs, errāssēs, if you had said this, you would have erred;
sapientia nōn expeterētur, sī nihil efficeret, philosophy would not be desired, if it accomplished nothing;
cōnsilium, ratiō, sententia nisi essent in senibus, nōn summum cōnsilium majōrēs nostrī appellāssent senātum, unless deliberation, reason, and wisdom existed in old men, our ancestors would not have called their highest deliberative body a senate.
2. Sometimes the Imperfect Subjunctive is found referring to the past, especially to denote a continued act, or a state of things still existing; as,—
Laelius, Fūrius, Catō sī nihil litterīs adjuvārentur, numquam sē ad eārum studium contulissent, Laelius, Furius, and Cato would never have devoted themselves to the study of letters, unless they had been (constantly) helped by them;
num igitur sī ad centēsimum annum vīxisset, senectūtis eum suae paenitēret, if he had lived to his hundredth year, would he have regretted (and now be regretting) his old age?
3. The Apodosis in conditional sentences of this type sometimes stands in the Indicative (Imperfect, Perfect, or Pluperfect), viz.—
a) Frequently in expressions of ability, obligation, or necessity; as,—
nisi fēlīcitās in sōcordiam vertisset, exuere jugum potuērunt, unless their prosperity had turned to folly, they could have thrown off the yoke;
NOTE.—In sentences of this type, however, it is not the possibility that is represented as-contrary-to-fact, but something to be supplied in thought from the context. Thus in the foregoing sentence the logical apodosis is et exuissent understood (and they would have shaken it off). When the possibility itself is conditioned, the Subjunctive is used.
eum patris locō colere dēbēbās, sī ūlla in tē pietās esset, you ought to revere him as a father, if you had any sense of devotion.
b) With both the Periphrastic Conjugations; as,—