In
ancient Roman religion,
augurs interpreted the flights of birds to ascertain the will of the gods, in response to specific questions. Their system was complex; for example, while a bird-sign on the left was usually favourable (auspicious) and one on the right unfavourable (inauspicious), the combination of a raven on the right and a crow on the left was favourable. Augurs also studied the behaviour of domesticated, sacred chickens before embarking on important enterprises, such as a senatorial meeting, the passage of a new law, or a battle. These formal "divine consultations" by augurs are known as "taking the auspices".
Haruspices examined the liver, lungs and entrails of
animals sacrifice to interpret the will of the gods, again in response to clear and specific proposals. Some omens came in the form of
prodigies – unnatural, aberrant or unusual phenomena such as
meteor showers,
hermaphrodite births, or "
blood rain", any of which could signify that the gods had somehow been angered. The meaning and import of reported prodigies were officially debated and decided by the
Roman Senate, with advice from religious experts. Threatening signs could then be officially expiated and the gods placated with the appropriate sacrifice and rituals. The interpretation and expiation of omens that suggested a threat to the State was a serious business. In 217 BC the consul
Gaius Flaminius "disregarded his horse's collapse,
the chickens, and yet other omens, before his disaster at Lake Trasimene". Certain natural events, particularly lightning strikes and thunder, could be ominous for the public or state, or only for the individual who saw or heard them. When a thunderclap interrupted his election as consul,
Marcellus gave up his candidacy. Thereafter he travelled in an enclosed litter when on important business, to avoid sight of any bad omens that might affect his plans. Many Romans believed that particular words, phrases or incidents might carry prophetic content aimed at particular individuals who witnessed or heard them. Such "private" omens could be accepted, and their benefits secured (or their threat averted) by use of countersigns, or verbal formulas such as ("I accept the omen, I hold to it"); the consul
L Aemilius Paullus, when about to embark on his campaign against
King Perseus, heard his daughter say that her dog Persa had died; given the similarity of the names and the death of the dog, he took this as a sign that Perseus would be defeated – which he was. was skeptical of unsolicited, personal omens. He reports the story that
Licinius Crassus took ship for Syria despite the ominous call of a fig-seller – ("Caunean figs!"), which might be heard as ("Beware, don't go!") – and was killed on campaign. Cicero saw these events as merely coincidental; only the credulous could think them ominous. In
Suetonius's "Lives of the Caesars", the deaths of various emperors are presaged by omens and dreams; the emperor
Caligula, for example, dreamt that he stood before the throne of
Jupiter, king of the gods, and Jupiter kicked him down from heaven to earth; Caligula ignored the premonition and was assassinated the next day. ==Astrology==