Republican Nobiles 293category. Unsolicited signs were the auspicia oblativa, signs occurring without being
asked for and usually indicating divine assent or dissent for a concrete undertaking;
prodigies also belong to this group. Although this classification does not stand closer
investigation – dreams, for example, were far from being self-evident and flocks
of professional dream-interpreters made their living from this; the distinction be-
tween solicited and unsolicited auguries may depend on the situation – it gives an
impression of the variety of divination techniques used in the Roman world. The
two most important types of public divination during the republic were prodigies
and auspices.Prodigies
Prodigies may be defined as unusual events signifying the wrath of the gods and a
disruption to the pax deorum, the “peace” with the gods. Thus, a prodigium– the
Romans also used the terms portentumor ostentum – was always a bad sign.
Prodigies did not occur on a special day in the year, did not point at an individual,
but at the res publica, did not foretell the future, and were expiated by Roman officials
usually at the beginning of the new year. As prodigies were classified, for example,
lightning striking important buildings or sites, monstrous births like children with two
heads, speaking animals, wild animals entering the city of Rome, eclipses, meteors,
comets, and rainfalls of blood, milk, meat, or stones.
Although no ancient author gives a detailed description of the procedure that turned
an unusual event into a prodigy, the following model can be reconstructed with some
degree of certainty. First, the unusual sign had to be announced to a magistrate,
usually a consul or a praetor (nuntiatio). The magistrate would then report the sign
in the senate, in some cases taking a witness with him (relatio). The senate had the
right to accept or to refuse the sign. Once a prodigy was accepted (susceptio), the
senate had the power to decide which ritual to perform to expiate the prodigium.
Usually, the senate would hand over this task to specialized priests: the pontiffs, the
decemvirs (since Sulla, a college of 15 priests), and the haruspices. Usually, only one
of the three priesthoods was asked for its opinion. The priests retired to consult their
holy books, which contained ritual texts, not prophetic utterances; the pontiffs used
the libri pontificum, the decemvirs the Sibylline Books, and the haruspicesthe libri
rituales. The powers of these priesthoods were narrowly defined. The senate could
accept, refuse, re-interpret, or amplify the advice of the priests. Since the colleges of
the pontiffs and the decemviriconsisted solely of senators, the senate held ultimate
control of the prodigies. The priests functioned as subcommittees of the senate. Because
Roman religion was by no means as rigid and unchangeable as believed in publica-
tions until almost the end of the twentieth century, but open to change, this model
might be subject to modifications over time. Thus it is not clear whether prodigies
were debated and interpreted immediately after they were reported or at the end of
the old year.
Our sources for Roman prodigies are rare and often brief to the point of obfus-
cation. Livy mentions prodigies, and sometimes their expiation, at the beginning or
at the end of a year. Iulius Obsequens, an author probably of the fourth centuryad,