Thus religion everywhere met the public life of the Roman by its festivals, and laid an equal yoke on his private life by its requisition of sacrifices, prayers, and auguries. All pursuits must be conducted according to a system, carefully laid down by the College of Pontiffs. Sacrifices and prayers of one or another kind were demanded during most of the occasions of life. Hidden in our word "inaugurate" is the record of the fact that nothing could be properly begun without the assistance of the augurs. Sacrifices of lustration and expiation were very common, not so much for moral offences as for ceremonial mistakes. The doctrine of the opus operatum was supreme in Roman religion. The intention was of little importance; the question was whether the ceremony had been performed exactly in accordance with rule. If not, it must be done again. Sometimes fifty or a hundred victims were killed before the priestly etiquette was contented. Sometimes magistrates must resign because the college of augurs suspected some informality in the ceremonies of their election. Laws were annulled and judicial proceedings revoked for the same reason. If the augurs declared the signs unfavorable, a public meeting must be adjourned and no business done. A single mistake in the form of a prayer would make it ineffectual. If a man went out to walk, there was a form to be recited; if he mounted his chariot, another. All these religious acts were of the nature of charms, which acted on the gods by an inherent power, and compelled them to be favorable, whatever their own wishes might be. The gods were, therefore, as much the slaves of external mechanical laws as the Romans themselves. In reality, the supreme god of Rome was law, in the form of rule. But these rules afterward expanded, as the Roman civilization increased, into a more generous jurisprudence. Regularity broadened into justice.[289] But for a long period the whole of the Roman organic law was a system of hard external method. And the rise of law as justice and reason was the decline of religion as mere prescription and rule. This one change is the key to the dissolution of the Roman system of religious practices.

The seat of Roman worship in the oldest times was the Regia in the Via Sacra, near the Forum. This was the house of the chief pontiff, and here the sacrifices were performed[290] by the Rex Sacrorum. Near by was the temple of Vesta. The Palatine Hill was regarded as the home of the Latin gods, while the Quirinal was that of the Sabine deities. But the Penates of Rome remained at Lavinium, the old metropolis of the Latin Confederation, and mother of the later city. Every one of the highest officers of Rome was obliged to go and sacrifice to the ancient gods, at this mother city of Lavinium, before entering on his office.

The old worship of Rome was free from idolatry. Jupiter, Juno, Janus, Ops, Vesta, were not represented by idols. This feature was subsequently imported by means of Hellenic influences coming through Cuma and other cities of Magna Græcia. By the same channels came the Sibylline books. There were ten Sibyls,—the Persian, Libyan, Delphian, Cumæan, Erythræan, Samian, Amalthæan, Hellespontine, Phrygian, and Tiburtine. The Sibylline books authorized or commanded the worship of various Greek gods; they were intrusted to the Decemviri.

Roman worship was at first administered by certain patrician families, and this was continued till B.C. 300, when plebeians were allowed to enter the sacred colleges. A plebeian became Pontifex Maximus, for the first time, B.C. 253.

The pontiffs (Pontifices) derived their name (bridge-builders) from a bridge over the Tiber, which it was their duty to build and repair in order to sacrifice on either bank. They possessed the supreme authority in all matters of worship, and decided questions concerning marriage, inheritance, public games.

The Flamens were the priests of particular deities. The office was for life, and there were fifteen Flamens in all. The Flamen Dialis, or priest of Jupiter, had a life burdened with etiquette. He must not take an oath, ride, have anything tied with knots on his person, see armed men, look at a prisoner, see any one at work on a Festa, touch a goat, or dog, or raw flesh, or yeast. He must not bathe in the open air, pass a night outside the city, and he could only resign his office on the death of his wife. This office is Pelasgic, and very ancient.