falsus, ut
timere desinam, _relieve me of this fear; if it is well founded, that I
may not be destroyed; but if it is groundless, that I may cease to
fear_.

4. Nisi has a fondness for combining with negatives (non, nemo, nihil);
as,--

nihil cogitavit nisi caedem, _he had no thought but murder_.

a. Non and nisi are always separated in the best Latinity.

5. Nisi forte, nisi vero, nisi si, _unless perchance, unless indeed_ (often
with ironical force), take the Indicative; as,--

nisi vero, quia perfecta res non est, non videtur punienda, _unless
indeed, because an act is not consummated, it does not seem to merit
punishment_.

Conditional Clauses of Comparison.

307. 1. Conditional Clauses of Comparison are introduced by the particles,
ac si, ut si, quasi, quam si, tamquam si, velut si, or simply by velut or
tamquam. They stand in the Subjunctive mood and regularly involve an
ellipsis (see Sec. 374, 1), as indicated in the following examples:--

tantus patres metus cepit, velat si jam ad portas hostis esset, _as
great fear seized the senators as (would have seized them) if the enemy
were already at the gates_;

sed quid ego his testibus utor quasi res dubia aut obscura sit, _but
why do I use these witnesses, as (I should do) if the matter were
doubtful or obscure_;

serviam tibi tam quasi emeris me argento, _I will serve you as though
you had bought me for money_.

2. Note that in sentences of this kind the Latin observes the regular
principles for the Sequence of Tenses. Thus after principal tenses the
Latin uses the Present and Perfect (as in the second and third examples),
where the English uses the Past and Past Perfect.

Concessive Clauses.

308. The term 'Concessive' is best restricted to those clauses developed
from the Jussive Subjunctive which have the force of _granted that_, etc.;
(see Sec. 278) as,--

sit fur, sit sacrilegus, at est bonus imperator, _granted that he is a
thief and a robber, yet he is a good commander_;

haec sint falsa, _granted that this is false_;

ne sit summum malum dolor, malum certe est, _granted that pain is not
the greatest evil, yet it is certainly an evil_.

Adversative Clauses with _Quamvis_, _Quamquam_, etc.

309. Clauses introduced by quamvis, quamquam, etsi, tametsi, cum,
_although_, while often classed as 'Concessive,' are yet essentially
different from genuine Concessive