devotion_.

b) With both the Periphrastic Conjugations; as,--

si Sestius occisus esset, fuistisne ad arma ituri, _if Sestius had been
slain, would you have proceeded to arms?_

si unum diem morati essetis, moriendum omnibus fuit, _if you had
delayed one day, you would all have had to die_.

Protasis expressed without _Si_.

305. 1. The Protasis is not always expressed by a clause with si, but may
be implied in a word, a phrase, or merely by the context; as,--

alioqui haec non scriberentur, _otherwise_ (i.e. if matters were
otherwise) _these things would not be written_;

non potestis, voluptate omnia dirigentes, retinere virtutem, _you
cannot retain virtue, if you direct everything with reference to
pleasure_.

2. Sometimes an Imperative, or a Jussive Subjunctive, serves as Protasis.
Thus:--

cras petito, dabitur, _if you ask to-morrow, it shall be given you_
(lit. _ask to-morrow_, etc.);

haec reputent, videbunt, _if they consider this, they will see_ (lit.
_let them consider_, etc.);

roges Zenonem, respondeat, _if you should ask Zeno, he would answer_.

Use of _Nisi_, _Si Non_, _Sin_.

306. 1. Nisi, _unless_, negatives the entire protasis; si non negatives a
single word; as,--

ferreus essem, nisi te amarem, _I should be hard-hearted unless I loved
you_; but--

ferreus essem, si te non amarem, _I should be hard-hearted if I did
_NOT_ love you_.

In the first example, it is the notion of _loving you_ that is negatived,
in the second, the notion of _loving_.

2. Si non (si minus) is regularly employed:--

a) When an apodosis with at, tamen, certe follows; as,--

dolorem si non potuero frangere, tamen occultabo, _if I cannot crush my
sorrow, yet I will hide it._

b) When an affirmative protasis is repeated in negative form; as,--

si feceris, magnam habebo gratiam; si non feceris, ignoscam, _if you do
it, I shall be deeply grateful; if you do not do it, I shall pardon
you_.

a. But if the verb is omitted in the repetition, only si minus or sin
minus is admissible; as,--

hoc si assecutus sum, gaudeo; si minus, me consolor, _if I have
attained this, I am glad; if not, I console myself_.

3. Sin. Where one protasis is followed by another opposed in meaning, but
affirmative in form, the second is introduced by sin; as,--

hunc mihi timorem eripe; si verus est, ne opprimar, sin