Vacancies in the body of pontifices were originally filled by co-optation; but from the second Punic War onwards the pontifex maximus was chosen by a peculiar form of popular election, and in the last age of the republic this held good for all the members.
Otherwise, reference was made for an interpretation to the pontifices in olden times,afterwards frequently to the Sibylline books,or the Etruscan haruspices, when the incident was not already provided for by a rule, as, for example, that it was unlucky for a person leaving his house to meet a raven, that the sudden death of a person from epilepsy at a public meeting was a sign to break up the assembly.
Hats were seldom worn except by those who affected Greek fashions, but the close-fitting leather pileus seems to have been an article of early wear in Italy, since its use survived in the ceremony of manumission, and the head-dress of the pontifices and flamines (cf.
He instituted the flamens (sacred priests) of Jupiter, Mars and Quirinus; the virgins of Vesta, to keep the sacred fire burning on the hearth of the city; the Salii, to guard the shield that fell from heaven; the pontifices and augurs, to arrange the rites and interpret the will of the gods; he also divided the handicraftsmen into nine gilds.
On the other hand, as the result in part of the theory of Stoicism, religion passed into the hands of the politicians: cults were encouraged or suppressed from political motives, the membership of the colleges of pontifices and augurs, now conferred by popular vote, was sought for its social and political advantages, and augury was debased till it became the meanest tool of the politician.
The collegium of the Pontifices was the most important priesthood of ancient Rome, being specially charged with the administration of the jus divinum, i.e.
The immense authority of the college centred in the pontifex maximus, the other pontifices forming his consilium or advising body.
When Lucullus assumed the command of the Roman troops in Asia, Caesar returned to Rome, to find that he had been elected to a seat on the college of pontifices left vacant by the death of his uncle, C. Aurelius Cotta.
Included in the collegium were also the rex sacrorum, the flamines, three assistant pontifices (minores), and the vestal virgins, who were all chosen by the pontifex maximus.
On the former date, the flamen Quirinalis, assisted by the vestals, offered sacrifice, and the pontifices presided at horse and chariot races in the circus.