ods needed the
help of the State's care and worship.

The ways and means towards the maintenance of this _pax_ were as
follows. First, the deities must be duly placated, and their powers kept
in full vigour, by the ritual of sacrifice and prayer, performed at the
proper times and places by authorised persons skilled in the knowledge
of that ritual. Secondly, there must be an exact fulfilment of all vows
or solemn promises made to the deities by the State or its magistrates,
or by such private persons as might have made similar engagements.
Thirdly, the city, its land and its people, must be preserved from all
evil or hostile influences, whether spiritual or material or both, by
the process broadly known as _lustratio_, which we commonly translate
_purification_. Lastly, strict attention must be paid to all outward
signs of the will of the gods, as shown by omens and portents of various
kinds. This last method of securing the _pax_ became specially prominent
much later in Roman history, and I prefer to postpone detailed
discussion of it for the present; but the other three we will now
examine, with the help of evidence mainly derived from facts of cult,
not from the fancies of mythologists.

First, then, I take sacrifice, dealing only with the general principles
of sacrificial rites, so far as we can discern them in the numerous
details which have come down to us. The word _sacrificium_, let us note,
in its widest sense, may cover any religious act in which something is
made _sacrum_, _i.e._ (in its legal sense) the property of a deity;[347]
I am not now concerned to conjecture what exactly may have been the
meaning of this immortal word before it was embodied in the _ius
divinum_. "Sacrificium" is limited in practical use by the Romans
themselves to offerings, animal or cereal, made on the spot where the
deity had taken up his residence, or at some place on the boundary of
land or city (_e.g._ the gate) which was under his protection, or (in
later times at least) at a temporary altar erected during a campaign.
Thus it was as much a sacrificium when the paterfamilias threw at each
meal a portion of the food into the fire, the residence of Vesta, as
when the consul offered a victim to Mars on the eve of a battle.

Sacrifices have generally been divided into the three classes of (1)
honorific, where the offering is believed to be in some sense a gift to
the deity; (2) piacular, or sin-offerings, where the victim was usua