Although astrology failed to play as influential a part in the life of any emperor during the last three centuries of the history of Imperial Rome as it had in the lives of, say, Tiberius or Nero, it did not suffer an eclipse.
On the contrary, it remained an absolutely integral part of Roman life. Sufficient horoscopes have survived to show that anyone with the means to consult an astrologer did so as a matter of course. Some of them tell us in considerable detail about the lives and ambitions, weaknesses and strengths of ordinary citizens. Apart from that, there were public manifestations of a general interest in the constellations and the planets: the huge eagle of Zeus on the ceiling of the sanctuary of Bel at Palmyra, for instance, was surrounded by the zodiac; at the races, chariots were started from stalls, each one of which bore a sign of the zodiac, and then raced around a circuit where each course represented that of one of the seven planets (hot competition, no doubt, for the one representing Mercury!). Even the division of the year into weeks of seven days, each subordinate to one of the planets, indicates how deep-rooted was the idea that the meaning of the universe was somehow geared to the movement of the planets in their courses.
The imagery of astrology was everywhere. One of the most famous examples is the feast described by Petronius in the Satyricon, given by the freedman Trimalchio, who sat his guests around a table on which various dishes were set out under the signs of the zodiac - beef under Taurus, sweetbreads and kidneys under Gemini, a balance with a tart on one scale and a cheesecake on the other under Libra, two mullets under Pisces, and so on.
Juvenal mentions several instances of people consulting astrologers, and although he was given to satirical exaggeration, we get a very firm impression of how the upper echelons of Roman society employed them: children would enquire about the time when their parents might be expected to die, women whether their lovers would survive them, and some people positively would not stir abroad without an astrological consultation:
Remember to avoid the tracks of women in whose hands you see (as if they were large gems) much-used ephemerides [tables of planetary movements]. Such a woman does not consult any astrologers; she is herself consulted. Nor will she accompany her husband when he goes to camp, or returns home, if warned against doing so by the numerical manual of Thrasyllus. She will not even go out as far as the first milestone unless a favourable hour has been chosen first from the book. When the rubbed corner of her eye itches, she will ask for a soothing balm only after consulting her horoscope. She may lie in bed sick; then no hour will be considered more apt for taking some food than the one which Petosiris has named ...
For those who found astrology suspect, and were properly outraged by the superstitious dependence upon it of the unthinking, there came something of a respite for a year or two after AD 96, when Nerva succeeded Domitian as Emperor; although the senators are said to have consulted his horoscope before electing him, his interest in the subject was marginal. Trajan, who succeeded Nerva in 98, was even less interested, although he seems to have been in touch with the grandson of Balbillus, who turned up in Athens. C. Julius Antiochus Epiphanes Philopappus (the ruins of whose monument still stand in Athens) was born during Nero's reign, and grew up safely at the court of his paternal grandfather Antiochus IV, last King of Commagene, at Samosata. Trajan not only made Philopappus a member of the imperial guard, but a consul. The nature of their relationship is unknown, however.
With the accession of Hadrian in 117, astrology once more approached the throne - indeed, mounted it, for the new Emperor was himself an astrologer, whose interest in the subject seemed to stem from his early teens, spent studying Greek and Roman culture in Rome, before being sent into the army by his guardian Trajan. He cordially disliked army life, and consulted at least two astrologers to ask for confirmation of the prediction apparently made at his birth, when his great-uncle Aelius Hadrianus, an astrologer, had promised he would one day be emperor. Confirmation was enthusiastically given.
Hadrian is the first Roman emperor whose complete horoscope has survived (in several manuscript copies among a selection of horoscopes kept by Antigonus of Nicaea, where they were found by Hephaestion of Thebes in the 4th century). We know that Hadrian was born with the Sun, Moon and Jupiter in Aquarius, Saturn and Mercury in Capricorn, Venus and Mars in Pisces - suggesting, among other things, great ambition and a preoccupation with power, arrogance and obstinacy, a high sense of justice, and a tendency to be ruled entirely by the emotions in personal relationships, which would tend to be unconventional. Interestingly, those with the Moon in Aquarius are traditionally said to have a flair for astrology.
Hadrian drew up his own horoscope and consulted it regularly; he is said to have written down on the first of January each year the major events of his life for the following twelve months, and to have predicted the time of his death to the hour. He was intensely superstitious, and interested in all forms of divination. His empress, Sabina, had rather a chill time of it, childless and rejected by her husband in favour of such beautiful young men as Antinous, who he even took with him on his last great ceremonial tour to Athens, on through Asia Minor to Egypt, and back to Italy through Syria and Athens again. Sabina was comforted on that tour by the presence of her lady-in-waiting and friend Julia Balbilla, a considerable poet, and none other than the great-granddaughter of Thrasyllus, who being the descendant of a king and a Roman knight was on easy terms with her mistress.
We do not know whether Julia had an interest in astrology greater than the normal; nor do we know whether Hadrian or any of his consultant astrologers foretold the central event of the tour - the death of Antinous by drowning in the Nile. There is a dark hint in Cassius Dio that Antinous may have sacrificed himself, or even perhaps have been sacrificed, because an astrologer had foretold the Emperor's own death unless someone of importance elected to die for him (remember, Balbillus had told Nero in 64 that only by killing some of Rome's noblemen could he escape death). Certainly his astrologers tried to console Hadrian by pointing to the convenient new star as the soul of his favourite, now shining in heaven. Astronomers still refer to Antinoos.
When Hadrian fell mortally ill in 136, interest in the succession focused on two men: Lucius Ceionius Commodus who, as Aelius Verus, he proclaimed his official successor, and Pedanius Fuscus, who at his birth had been stamped by astrologers as a coming emperor. At the time when Aelius Verus was proclaimed, he was already too ill to make a speech of thanks to the senate, and it seems that Hadrian was relying on a horoscope (drawn up either by himself or someone else) which had promised him a long life. When an astrologer suggested to the Emperor that there was some mistake - the wrong birth time had been used, perhaps - Hadrian answered: 'It is easier for you to say that when you are looking for an heir to your property, rather than to the empire.' Anyway, Aelius Verus died before Hadrian, who was left with the necessity of making another choice.
This fell upon Antoninus Pius, on condition that he adopted L. Verus (Aelius Verus' son) and an older boy, Marcus Aurelius, as his own heirs. Pedanius Fuscus was outraged, foolishly became involved in a plot to seize the throne, and was arrested and executed. A surviving horoscope by Antigonus of Nicaca says that he 'was born to become, at the age of 25, the cause of his own destruction and that of his parents', and gives the reasons for his fall - which include his being ill-advised because Mercury and Saturn were in a male sign, being discovered in a plot because the Moon was in Scorpio, and dying because Mars and Aquarius rose at the same time.
Antoninus Pius, who reigned between 138 and 161, and Marcus Aurelius (161-180), seem to have had few formal dealings with astrologers; at least, there is no record of any, and it has been conjectured that this was because of the increased influence of Stoic philosophy in Rome. If the future is absolutely fixed, then no amount of foreknowledge can make any difference; and in that case, what is the point of prediction?
As might be expected, however, Aurelius accepted astrology as a useful tool. He was interested too in dreams as a means of divination. He had the horoscopes of his twin sons drawn up, when they were born in August 161. Both were favourable, and the fact that the elder boy died when he was four does not seem to have shaken the Emperor's faith. He settled the succession on his younger son, Commodus.
As unattractive a personality as ever sat on the throne of Rome, Commodus' spare time was spent enjoying himself in tavern or brothel, or stripped naked to take part in gladiatorial combat in the public arena. He was as much star-worshipper as genuine astrologer, and saw astrology as some kind of superstitious quasi-religion rather than as a scientific system. His successor, Septimus Severus, returned to a more sensible, practical view. Born in Africa, he rose to high rank under Marcus Aurelius, and is known to have consulted an astrologer about his own destiny. His promotion to the tribunate in 176 confirmed that good fortune was accurately foretold. During a brief eclipse from favour under Commodus, he advertised for a marriageable woman whose horoscope should conform to his own, and found one in a Syrian, H. Julia Donna, who bore him two sons, one of whom was nicknamed Caracalla.
Severus was unwise enough, when praetorian governor of Sicily, to be discovered once more consulting an astrologer about his 'imperial destiny', as Cassius Dio put it. But (because, the historian suggested, Commodus was so cordially detested) the local authorities did not prosecute him; indeed, they crucified the unfortunate man unwise enough to have betrayed him!
After the death of Commodus and a short period of struggle for the throne, Severus occupied it, supported in his bid for power by the prognostications of several astrologers and by other miscellaneous divinations. Decorating his new imperial palace, he had his horoscope painted on the ceilings of the rooms in which he held court - although not in such detail as to give away to the casual observer the precise moment of his birth, so the horoscope could be used against him.
Severus seems to have been almost manic in his acceptance of any astrological prediction made with sufficient assurance, although the stoical attitude of some of his predecessors was entirely absent in him, and he evidently believed that if he intervened with determination in the planetary plan, he could depend on some mitigation of astrological prophesy. For instance, he executed numerous people - including several of his friends - on the grounds that they had consulted astrologers to discover the best time at which to assassinate him.
Severus is said to have left Rome for Britain in the knowledge that he would not survive the campaign there. Caracalla, having murdered his younger brother Geta, for safety's sake, seems to have had the same total belief in astrology as his father. Astrologer after astrologer was summoned to advise him, and several of them - an Egyptian called Serapio, one called Ascletion, and Larginus Proculus-told the Emperor that he would not live long, and that his successor would be Macrinus, a prefect. Ascletion was executed, Larginus Proculus was promised execution immediately after the date on which he had said Caracalla would die, and Serapio was thrown to a lion (which simply licked his hand, so a more prosaic execution had to be arranged).
Nevertheless, Caracalla was murdered, and for the next several decades astrology took a less prominent part in imperial manceuvrings. Neither Opellus Macrinus, who reigned only for a year, nor Elagabalus, a demented young man who took the name of his Sun god and was slaughtered when he was 18 by his praetorian guard, contributed anything to its history; and Severus Alexander, who reigned between 222 and 235, was said to be an astrologer but did not use the skill ostentatiously.
What he did do was encourage professional astrologers to organize themselves into a body that could pass on knowledge in a proper manner, actually advertising themselves as teachers; and he seems to have seen to it that astrology was given precedence when the curriculum at the Athenaeum in Rome, founded by Hadrian, was reorganized.
As the power and influence of Rome passed its apogee, Christianity began to increase its hold, and eventually under Constantine in 334 was to be proclaimed as the official state religion, thus doing astrology the enormous service of reducing it from the status of a religious and magical art to that of a science. What, during these first centuries AD, was the state of the theory and literature of the subject?
The Tetrabiblos has already been mentioned as probably the most distinguished of astrological textbooks. The Anthologiae of Vettius Valens was enormously popular, perhaps because whereas Ptolemy wrote substantially for the educated layman and explored the subject scientifically, Valens was himself an astrologer, and intended his work for believers.
We know little of the life of Vettius Valens, except that he never grew rich, was never involved in politics or fashion and so, avoiding execution for favouring this imperial candidate or that, remained relatively unknown. He seems to have bolstered his income by running, for a time, a school of astrology (he dedicated his book to one of his students, Marcus). It is impossible to reconstitute the Anthologiae, which was in nine books; but it was to be used by generations of astrologers up until the 8th century at least, when Theophilus was still quoting it.
Some popular astrological writing was in verse: among the astrological versifiers were Astrampsychus, Dorotheus of Sidon, and Manetho. Astrampsychus left a hundred and one astrological aphorisms, printed in alphabetical order. Anubio, who may have been an Egyptian, left work which was to be used by Firmicus Magnus, Hephaestion, Palchrus and Rhetorius, over the next four centuries. Dorotheus, an Arab, left his Pentateuch, five books, dealing with births, eras of time, the Lords of the Horoscope, the computation of birth years, and 'undertaking' or the divination of events in a life. And to the professional astrologers must be added those who believed astrology to be an important part of their studies, like the physicians Antigonus of Nicaea and Galen.
Medical astrology was already beginning to rationalize its beliefs. These were never fatalistic; after all, if fate determined whether or not a patient should recover from or succumb to an illness, what point would there be in treating him? Galen (130-c200) studied medicine at Pergamos, where he was born, then in Corinth and Alexandria, and finally in Rome (where he became physician to Marcus Aurelius, and later attended Commodus and Severus). He was careful always to note the precise time at which a patient had taken to bed with an illness; carefully considered the position of Sirius, the dog star, when medicine was being prepared or administered; insisted that the theriac, a medicine which he had developed, should be taken at the third hour of the first or fourth day of the Moon; and in one of his medical treatises devoted twelve chapters to the influence of the Moon in each of the zodiac signs, also dealing with the positions of the planets. Antigonus went further, publishing a collection of 'medical horoscopes' which doctors used for at least two centuries to help them in treating patients.
Not a single writer, as far as can be discovered, argued that the planets could have no influence on human affairs, although there were many arguments about the degree to which they enabled a practitioner to predict events, or delineate character. The most distinguished of the 'opponents'of astrology, or those who believed that astrologers' powers of divination were extremely limited, was Plutarch (c 46-120), a journalist who wrote on philosophy, morals and, of course, biography. He never organized or even rationalized his objections to astrology, simply pointing out that man had a very generous capacity for accepting anything 'magical', and arguing strongly against the conception of an immutable fate.
He had little effect on the faithful. In the 2nd century came a more considerable antagonist of fatalistic astrology, Favorinus of Arles, who seems to have had many an argument on the subject with the Emperor Hadrian, who was of course of a very different persuasion. Favorinus' arguments were not always very well-founded: for instance, he believed that astrology was a new fad, and that astrologers had invented the so-called ancients who they claimed had founded the art. He then (and this argument is reiterated to this day) claimed that all astrological predictions were so general as to be meaningless; went on to say that anyway, man's time on earth was far too brief for him to be able to fathom such a complicated theory; asked how astrology could be used to forecast the weather when good and bad weather existed at the same time in different places; demanded to know why the time of birth under one constellation should be considered when the time of conception under another was ignored (a good point); doubted whether the precise moment of birth could ever be discovered; and - another appealing point - asked whether it was not ridiculous and unbearable to suggest that all our actions, down to deciding whether or not to take a bath, were predestined.
Ptolemy disposes of most of these criticisms. But in any case opposition was not (any more than defence) on rational grounds. Someone who heard Favorinus give an anti-astrological lecture described how he summed up:
Astrologers predict either adverse or propitious events. If they foretell prosperity and deceive you, you will be made wretched by vain expectations; if they foretell adversity, you will be made wretched by useless fears ... The anticipation of your hopes will wear you out with suspense. Therefore there is every reason why you should not resort to men of that kind who profess knowledge of the future.
One of the ironies of Roman astrological history is that so many emperors who almost uncritically accepted the influence of the planets patronized scholars who argued against it. Favorinus had argued with Hadrian; Septimus Severus, almost fanatically attached to the most fatalistic aspects of astrology, appointed Alexander of Aphrodisias to the chair of the Peripatetic School at Athens, from where he issued his essay On Fate, in which he denied that the planets could affect human destiny - though even he agreed that they must influence non-human aspects of life on earth, such as the elements, 'the creation, destruction, and in general all transformation of matter. They also determine all terrestrial motion.'
Astrology was included in the multifarious criticisms levelled at almost all human knowledge by Sextus Empiricus, the Greek physician and sceptic philosopher, who in the late 2nd and early 3rd centuries attacked literature and philology, rhetoric, geometry, arithmetic ('number is nothing'), music, logic and physics. Even he excepted astrological meteorology from his general condemnation, but as for individual horoscopes - they were nonsense! He summarized astrological knowledge as it was known in his time, and then demolished each point in turn - or attempted to. Some of his criticisms are entirely valid (the difficulty of knowing the precise birth time, for instance); others were based on misunderstandings (which seem, sometimes, almost contrived); and others were simply vapid. He asks for instance why 'someone born under Leo should be strong and brave just because that constellation is called Leo', or why someone born under Virgo should be considered likely to be fair while an Ethiopian born under the same sign would undoubtedly be swarthy. Silly sooth.
Sextus Empiricus' only really rational criticism, and one for which there was much to be said, was that there was just not enough scientific data known to astrologers to enable them to present their science as a science. But nevertheless, his arguments against astrology were to appeal to a band of people whose attitude to the subject, if often confused, was to affect its history for a thousand years and more. The Greek satirist Lucian, whose own attack on astrology lacked muscle, lashed out in his abhorrence of the subject at a relatively new cult, a gang of simpleminded followers of a crucified sophist, one Jesus Christ. The 'Christians' approached astrology with almost superstitious caution.