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Astrology in Medieval Europe

The early Middle Ages, while it produced a fair amount of argument about astrology, and saw a diminution of its influence on monarchs, did not mark as complete a collapse as some historians have suggested. Even where there was some doubt about its use on a personal level, it was still generally admitted to be useful in meteorology and agriculture. And most scholars took the view that it was an important element of general knowledge. Boethius, the 6th-century consul in Rome, some of whose writings were translated by King Alfred the Great, was one of them, and his book The Consolation of Philosophy must have been influential in reinforcing whatever knowledge of astrology there was in Britain in the 10th century. He argued that the movements of the planets derived from the immortal will of Providence, and that 'the celestial movement of the stars' translated that will into earthly events, 'constraining human forces in an indissoluble chain of causes which, since it starts from the decree of immovable Providence, must needs itself also be immutable.'

Nevertheless, he was not a fatalist, for even divine Providence imposed no fatal necessity on the human will, which was always free, while nature was not, but was constrained by the planets. As Canute found, you cannot argue with the tides. Boethius also, by the way, agreed with Plato that each planet has its own musical chord, contributing to the heavenly harmony of the music of the spheres.

An attraction of the astrological theory, in the early Middle Ages as now, was that it could be applied to absolutely every facet of human life.

But there were some areas into which it soaked with persuasive power, and among these was medicine. The 'astrological man' appears again and again in manuscripts of the period, though sometimes to denigrate astrology. There is for instance a splendid 11th-century drawing of the twelve signs grouped around the figure of Christ, hand raised to bless. The names of the parts of the body 'ruled' by the various signs appear - but the caption reads: 'According to the ravings of the philosophers the signs are thus denoted'!

Astrology was by now so integral a part of medicine that it was not to be possible to disentangle the two for many centuries. Until the 18th century it was still impossible to qualify as a doctor at some universities unless you had passed an examination in astrology, and the use of the planetary positions in diagnosis and treatment was a commonplace.

Like other theories, this was used to a greater or lesser degree according to the temperament of the physician. Constantinus Africanus, for instance, who lived between 1015 and 1087, was enormously important in the history of medicine mainly because of his translation and presentation of earlier medical textbooks. He had studied with Chaldeans, Arabs, Persians and Saracens as well as in Tunis (where he was born) and Baghdad. But in his Be humana natura, apart from tracing the formation of the embryo in the womb and relating this to the positions of the planets, and including a certain amount of mildly eccentric material (someone who consistently wets the bed, for instance, should eat the bladder of a river fish for eight days while the Moon waxes and wanes), he makes relatively little of astrological medicine, though there can be no doubt he studied it.

It is not surprising that Constantinus studied in the East, for collaboration between Jewish and Arabian scholars had resulted in a correlation of astrological knowledge at such centres as Cairo, Baghdad, Alexandria and Kairwan in Tunis, which produced at least one remarkable scholar in Isaac ben Solomon Israeli, or Isaac Judaeus, who worked there in the 900s, and wrote books on medical astrology which survived for centuries (Robert Burton quotes from him in The Anatomy of Melancholy).

To trace the various contributions to what might be called 'Arabian' astrology is an almost impossibly complex task, for pieces of theory drifted towards the Arabian centres from as far away as China and India, as well as from Rome, Greece, Egypt and Persia. This was collected together in the great library founded in Baghdad by Harun al-Rashid and al-Mamun, caliphs of the Abbasside dynasty, and completed in about 850, where apart from the lesser works there were Greek copies of the Tetrabiblos translated for general use.

There are hints of the importance of the work done in Baghdad in the writings, six or eight hundred years later, of some Englishmen. Chaucer, for instance, wrote a Treatise on the Astrolabe in the 14th century in which he made use of Messahala's Commentary on Ptolemy, written in the early 800s; William Lilly quotes from the same source in the 1640s; Dr Dee, in Elizabethan England, owned several manuscripts of Isaac Judaeus' works.

In other countries too the Arabian interest in astrology took hold; in Spain, for instance, where the Western Caliph founded in 948 an academy at Cordova at which Moors and Jews alike built up a body of knowledge which in its turn was disseminated through academies founded at Toledo and Granada. There, Hasdai ibn-Shaprut, a Jew, taught at the end of the 10th century, among other things rationalizing the assignation of all known herbs to separate planets which influenced their growth and virtue. Gerbert of Auvergne probably studied under him before being made Archbishop of Ravenna in 998, and later Pope, as Sylvester II. So there is evidence that Christians as well as Moors and Jews studied under Arabian auspices. Sylvester II was admittedly later accused of having had dealings with the Devil because of his studies at Cordova, and some Christians attempted to attach dark satanic inferences to anyone who had studied astrology; but progress was not, at this stage, to be denied.

Despite the vicissitudes of history - the capture of the Moorish cities of Spain by the Christians in the 11th century, for instance, and the driving out of the Jews - the 'universities' at such cities as Toledo continued to function for centuries, with a continual stream of scholars benefiting from their libraries and their tradition of scholarship, all of which unhesitatingly supported astrology as a serious study.

From the 9th and 10th centuries, visual reminders have survived that help demonstrate the subject's fascination - sometimes illustrating slight differences between eastern and western astrology. In Islamic countries, human beings could not be represented by artists, and so the 'human' zodiac signs were altered: in place of the Geminian twins, Muslim artists showed two peacocks; a wheatsheaf replaced the girl in Virgo, and Aquarius became a mule carrying two baskets.

There is at Florence a splendid example of another work of art, this time with a practical purpose: an astrolabe for the latitude of Rome, said to have belonged to Sylvester II. An equally early one is at Oxford, made in 984 by Ahmad and Malmud, sons of Ibrahim, of Ispahan. The development of the astrolabe began, it is believed, in the 1st century BC - there are claims for it as the oldest scientific instrument. Used for measuring the altitude of the stars, it was essential to the astronomer-astrologer, and there are many fine examples of astrolabes in museums. It was often magnificently decorated, a pleasure to look at as well as to use.

The spread of astrology across Europe, the extent to which it was practised in any western country before the growth of the Roman Empire, is a subject that must be treated with the utmost delicacy. It depends to some extent, of course, on what kind of astrology one is talking about. It seems fairly clear that natal astrology, the setting up of a map of the sky for the moment of a birth, the construction and interpretation of a horoscope, was not possible in, say, Germany, France or Britain until well into the time of Imperial Rome; and that if it was possible then, the means were only known to a very few people, and those probably attached to Roman armies as Balbillus had been attached to Claudius' entourage during his journey to Britain.

However, if we accept that an interest in astrology often arose from a preoccupation with the simple observation of planetary movements, then the most primitive civilizations showed it, and it may be said that Stonehenge - for instance - betrays such a preoccupation, if we are to accept that that monument (and others like it) was erected to fulfil some astronomical purpose.

The many theories about the planning and erection of Stonehenge are too complex to investigate here; but the theory that it was some kind of astronomical computer, while suspect in some quarters, is quite sufficiently well argued to remain a possibility. Whatever its purpose, there certainly seems to be an astronomical connection; and the influence on an ignorant community (we are speaking of something like 2900 BC) of a priestly aristocracy that could forecast even the most basic solar and lunar events would have been very considerable. It is even suggested that the people of Neolithic Britain were ruled by such an aristocracy, the leaders of which possessed at least some of the knowledge of the early Babylonian astronomers. Much of their power as leaders of society may have been derived from their knowledge of astronomy, used 'magically' to invoke the aid of those heavenly gods, the planets, in hunting: a sort of astrology, although at that stage invoking the occult as intensely as - if much more vaguely than - the Babylonians or Egyptians did.

Three thousand years later we glimpse a more sophisticated astrology in the British Isles: although still much too dimly to draw detailed conclusions. The Druids remain sufficiently mysterious to enable the inventive to saddle them with all sorts of preoccupations of which they may have known nothing. Caesar recorded that the Druids in Gaul were men of dignity, lawgivers and priests, learned in astrology and the natural sciences. Britain seemed to be the headquarters of the Druid cult, if that is what it was, and there was an annual meeting in Gaul from which the most promising novices travelled to Britain for training, where they seem to have studied not only astrology but the same systems of divination as the Babylonians - using patterns of bird flight, for instance, and the convulsions of dying men.

Early Christian literature provides examples of the Druids predicting a child's future from the date of its birth, and the word for cloud divination (neladoracht) is also freely used to mean astrology and divination in general. There are several references to astrology itself; for instance, it is related how an astrologer calculated the planets' positions in order to tell the foster-father of St Columkille, better known as St Columba of Ireland, when it was a propitious time for the boy to begin lessons. It is clear too that the Druids operated a system of lucky and unlucky days: the thirteenth day of a lunar cycle was considered a bad one on which to begin anything; a boy born on that day would be 'courageous, bold, rapacious, arrogant, self-pleasing', and a girl 'saucy, spirited, and daring of her body with many men'.

Little is known about the patterns of international travel in ancient times; however, it is by no means impossible that, as some scholars have suggested, astronomical knowledge of all sorts reached Britain and western Europe in the earliest years of Babylon; it does not seem very likely that men should otherwise spontaneously have started building stone circles and similar monuments in various parts of the western world at the same time. Such legends as those that support the coming of Mediterranean traders to Britain many centuries before Christ may be far from nonsense; and while it does not seem at all likely that men with the knowledge to design and build such a sophisticated monument as Stonehenge would be travelling on a trader's boat, there is nothing inherently absurd in the idea: scholars have often also been adventurers.

We begin to see our way rather more clearly round about the time of the Roman occupation, when Mithraism brought knowledge of the existence of astrology to Gaul, Germany and Britain, and temples to the Roman gods were built - often on the sites of Druidic temples, it seems, for Caesar says that the Gauls worshipped Mercury, Apollo, Mars and Minerva (and can only have meant that they worshipped local gods like those Roman ones).

With the departure of the Roman legions, and the Dark Ages, astrology like so much else vanishes from our view, except for some hints that the knowledge brought by the Romans was treasured by some scholars, especially in the north and west of the province - at the limits of Roman power, whence, eventually, came so many early scholars - Alcuin and Bede, Adelard and Roger Bacon among them. Did the British who had learned to read continue to treasure Roman books after AD 410? A few relics suggest the answer books in Greek or Latin with scribbled comments and notes in a Scottish or Welsh dialect.

Geoffrey of Monmouth (c 1100-1154), that early romancer and historian, claims that in King Arthur's reign, whenever that may have been,

there subsisted at Carleon in Glamorganshire a college of two hundred philosophers, who studied astronomy and other sciences; and who were particularly employed in watching the course of the stars, and predicting events to the king from these observations.

By the time Geoffrey was writing, Christianity had long been established in Britain; but as we have seen, this may well have meant increased knowledge and approval of astrology rather than the reverse.

Can Geoffrey's word be accepted, though? Well, he tells us that his Historia regum Britanniae is a translation of 'a certain very ancient book written in the British language' (that is, Welsh) by Walter, Archdeacon of Oxford. This may have been a simple, individual manuscript; in any event, it has completely vanished. Geoffrey may have invented some of his history, but he would not have invented it all - indeed his often garbled records of some events match with those of which we have knowledge, and he (or his original source) refers often to Cicero, Juvenal, Lucan, Apuleius and others. So the evidence that astrology was in use 'at the time of King Arthur' is worth something, if perhaps not a great deal.

Strands of astrological belief must have been preserved not only by the faint and fading tenets of whatever 'religion' had been supported by the Druids, but in the fading memories of Mithraism, if these communicated themselves to the British, and in the heritage of knowledge left by Rome; and Christianity contributed, too. In The Panegyric of Lludd the Great, a poem written in the 6th century by Taliesin, the 'mythical' British bard, there is a passage, among many dealing with prophesies, which reads

To Britain shall come an exaltation,

Britons of the stock of Rome,

May I be judged by the merciful God.

Astronomers are predicting

Misfortune in the land.

Druids are prophesying

Beyond the sea, beyond Britain,

That the summer shall not be fair ...

Of little value except as evidence, again, that some knowledge of astrology persevered. The Anglo-Saxon Chronicle agrees. This was written at various centres up to the mid-12th century; the earlier parts probably originated with King Alfred (871-900). It records various eclipses, and other planetary phenomena. (It also, incidentally, records the travels of the 'three astrologers' - rather than kings or wise men - to Christ's birthplace.) The Chronicle mostly interprets eclipses and comets as symbols of foreboding. In 664, we are told, an eclipse on 10 May brought not only the death of the King of Kent, but a plague; fourteen years later, a comet in August presaged Bishop Wilfrid's expulsion from his bishopric. The comet of 729 brought a clutch of disasters: St Egbert died, and the Atheling Osward, and Osric, King of Northumbria.

Among the astronomical reports appear records of more astonishing incidents: a number of fiery dragons flew over Northumbria in 793 (possibly the Leonide meteors); in 979 'was seen a bloody welkin oft times in likeness of a fire'. But for the most part the authors concentrate on comets and eclipses - including the most famous comet of all, Halley's, which appeared in 1066, and is shown in the Bayeux Tapestry above the head of the crowned King William the Conqueror.

By the beginning of the 8th century, the names of individual astrologers begin to appear: such men as Aldhelm, who was taught at the school in Kent started by Abbot Hadrian and his friend Theodore, Archbishop of Canterbury - the latter came from Tarsus in Asia Minor, and the two men certainly taught in Greek as well as Latin. Aldhelm left treatises on astrology, as well as on logic and arithmetic, meant as textbooks for future students. Alcuin, or Ealhwine, was educated at York, at a school with a long history (it has been suggested that its tradition went back to the Roman occupation), and went on to become a friend and adviser of the Emperor Charlemagne. He learned, he said, among other things, 'the harmony of the sky', the laws governing the rising and setting of the stars and the seven planets.

Some of the art and architecture of Britain before the 11th century has astrological references - sometimes at a distance, as when we hear for instance that the old Abbey of Glastonbury had a zodiac in its floor. There is zodiacal ornamentation in a number of pre-Conquest churches in Kent, and the new Canterbury Cathedral had some zodiac figures in it simply because the old one, burned down in 1067, had had them. There are 8th-century zodiacal drawings among the Harleian manuscripts in the British Library, and when the Abbey of Croyland was burned in 1091, according to a history compiled from ancient manuscripts that survived the fire,

we lost a most beautiful and precious table, fabricated of different kinds of metals, according to the variety of the stars and heavenly signs. Saturn was of copper, Jupiter of gold, Mars of iron, the Sun of lattern [a yellow metal like brass], Mercury of amber, Venus of tin, and the Moon of silver. The eyes were charmed, as well as the mind instructed, by beholding the coloured circles, with the Zodiac and all its signs formed with wonderful art of metals and precious stones, according to their several natures, forms, figures and colours.

After the Norman conquest a new flow of astrological material reached England with Jewish scholars from France and elsewhere who settled not only in London, Oxford and Cambridge, but in other large towns, bringing with them books which contained astrological lore, particularly from Arabic and Moorish sources. There is a tradition that William the Conqueror had his own astrologer, who set the time for his coronation (midday on Christmas Day, 1066) - and astrologers claim that this was a particularly auspicious moment, unlikely to have been chosen at random, and take it as the moment for which to set up a general 'horoscope' for England.

It was during William's reign that perhaps the most notable of 11th century English scholars was born, at Bath. Much of the life of Adelard, or Aethelhard, is dark to us, although he certainly travelled extensively in Europe, and perhaps further afield, for in one of his books he says with authority that 'what the schools of Gaul do not know, those beyond the Alps reveal; what you do not learn among the Latins, well-informed Greece will teach you.' He is fond, too, of quoting from Arabic texts, and does so, often, as though he is using verbal rather than literary sources.

Among his works are many on mathematics, astronomy and alchemy. He seems to have been somewhat strait-laced, or at least to have found the atmosphere of England uncongenial after his travels to more refined lands, for on his return he finds the country under Henry I filled with villainous fellows:

Princes are violent, prelates wine-bibbers, judges mercenary, patrons inconstant, the common men flatterers, promise-makers false, friends envious, and everyone in general ambitious.

He intends, he says, to settle down to serious work, and certainly did so. He translated several Arabic astrological works, including some (the tables of al-Khowarizmi, for instance) which were directed at teaching the reader to set up a horoscope. He would scarcely have done this had he not been interested in the subject, or indeed had been unable himself to set up a chart. His view was that the planets were 'superior and divine animals' which were 'the causers and principle of inferior natures'. One who studied then could understand the present and the past and predict the future. His charming view of the stars as celestial pets extends to a consideration of their food, which he believed consisted of the humidities of earth and water, refined by a long journey through the upper air, and which by the time they reached the planets were sufficiently light and ethereal not to dull their wits or make them put on weight.

Another treatise which was probably written by Adelard quotes from Hermes Trismegistus, Ptolemy, Apollonius and other ancient authorities, and argues for the use of astrology in medicine, for its study makes for better doctors than 'the narrow medical man who thinks of no effects except those of inferior nature merely'. He also deals with the planets' effects on animals and plants, and ascribes to them certain metals and colours - and indeed religions: the Jews are ruled by Saturn, the Arabs by Mars and Venus, Christianity by the Sun and Jupiter (for the Sun stands for honesty, liberality and victory, and Jupiter for peace, equity and humanity). The continual battles between the Jews, the Muslims and the Chrktians are explained by the fact that neither Mars nor Saturn is ever in friendly relation with Jupiter.

More or less contemporary with Adelard was William of Conches. He also travelled extensively before becoming associated with the court of Geoffrey Plantagenet as tutor of his son, the future King Henry II of England, between 1146 and 1149. Interestingly, William is one of the first scholars to attempt a definition of the difference between astronomy and astrology. Authorities, he says, speak of the planets in three ways: the fabulous, the astrological and the astronomical. Those interested in fables interpret the Greek myths as if they were astronomical. The astrologers treat phenomena as they appear to be, whether accurately or no. Astronomers deal with things as they are, whether they seem to be so or not.

He takes the argument no further, but does not seem to be intending to denigrate astrology, for he goes on to misquote Plato in support of the theory that the planets control nature and the human body. The heavenly bodies, he argues, heat the atmosphere, which in turn heats water - which forms a fundamental part of all animal bodies - and so must affect every living thing. He lists the planets and their qualities and humours, and puts forward some theories about how the principles were discovered, not only suggesting practical but symbolic reasons. The ancients, he suggests, discovered that Saturn was a 'cold' planet because when the Sun was cooler than usual it was in Cancer and in conjunction with Saturn in the same sign. But he also pointed out that Saturn was said to carry a scythe because a man who did so 'did more execution when receding than advancing'. Venus was said to have committed adultery with Mars because when those two planets were close together, Mars took away some of Venus' good influences.

It has been suggested that Henry II's interest in astrology, fostered by his tutor William of Conches and by his father Geoffrey, Count of Anjou, was sufficient to make him the patron of Abenezra (1092-1167), a Jew from Toledo, who came to England in 1158 to lecture in London and Oxford. He was also a poet:

The planets and stars in their courses

Made way when I first saw the light;

If I were a seller of candles

The Sun it would shine all the night.

I try to succeed, but I cannot,

For the heavenly spheres oppose;

If I took to winding-sheet sewing,

Then no-one would die, I suppose.

Abenezra seems to have had a pleasant sense of humour as well as considerable fame as an astrologer-writer (his De nativitatibus was reprinted in the 15th and 16th centuries). He lectured not only in England but all over Europe, and may briefly have occupied the chair of astrology at the university of Bologna.

Both Adelard and William of Conches were important in bringing to France and England more Arabic works, some of which they translated, and some of which they used as source material for their own books. There were of course other translators, many of whose names have been lost, though we know others - Bartholomew of Messina, Burgundio of Pisa and Eugenius, Admiral of Sicily, who translated from the Greek; Egidius de Trebaldis of Parma, Arnold of Barcelona and Blasius Armegandus of Montpellier, who translated from the Arabic, and so on. Through their work a great stream of astrological knowledge from Arabia made its way westward - some translators, like Pedro Alfonso, claimed to be intent on bringing knowledge westward to save greater scholars than he the labour of travelling so far to acquire the basis on which they could construct their philosophies.

Most translators and scholars believed in observation and experiment as well as the acquisition of knowledge from books. Pedro believed strongly in experience as a good master: 'It has been proved by experimental argument', he says, 'that we can truly affirm that the Sun and Moon and other planets exert their influences in earthly affairs... And indeed many other innumerable things happen on earth in accordance with the courses of the stars, and pass unnoticed by the senses of most men, but are discovered and understood by the subtle acumen of learned men who are skilled in this art.' He was, incidentally, physician to King Henry I of England, and left notes on astrological medicine. Twenty years after his death, Walcher, Prior of Malvern, made translations of all Pedro's books into English.

It was during the 12th century that a great acceleration occurred in the translation of astrological texts into Latin. By 1150, most major texts were available in that language - Plato of Tivoli had translated the Tetrabiblos (as the Quadripartitum); John of Seville made a version of the Centiloquium, a series of astrological aphorisms attributed (wrongly) to Ptolemy, and translated Albumasar, Alchabitius and Messahala. And Gerard of Cromona (1114-87) made over seventy translations from the Arabic into the Latin, among them Ptolemy's Almagest (Syntaxis), and two previously unknown works of Aristotle, the Meteorologica and the Generatione et corruptione.

By the end of the first decade of the 13th century, the complete works of Aristotle were for the first time available in Western Europe in a language that every scholar could read, and by 1255, despite the misgivings of some churchmen, they were accepted in the universities. This was a great step forward for astrology, for it meant that no serious theologian would now contest the fact that the processes of change and growth on earth depended on the activities of the heavenly bodies; read the medieval scholars on Aristotle, and we find them all - from Albertus Magnus to Thomas Aquinas and Dante - accepting the astrological theory which had become a part of the philosopher's arguments; if they held strongly to free will as a cornerstone of Christian teaching, they could not now deny Aristotle's (or, for that matter, Augustine's) admission that the planets influenced human affairs. The Church was forced to see astrology as a science, and recognized it while at the same time condemning magic. Thomas Aquinas is explicit in his Summa theologiae:

The majority of men ... are governed by their passions, which are dependent upon bodily appetites; in these the influence of the stars is clearly felt. Few indeed are the wise who are capable of resisting their animal instincts. Astrologers, consequently, are able to foretell the truth in the majority of cases, especially when they undertake general predictions. In particular predictions, they do not attain certainty, for nothing prevents a man from resisting the dictates of his lower faculties. Wherefore the astrologers themselves are wont to say that 'the wise man rules the stars' forasmuch, namely, as he rules his own passions.

The spate of translations from the Arabic introduced a new element into western astrology. Ptolemy in the Tetrabiblos had concerned himself almost entirely with judicial astrology - using the positions of the planets at the time of someone's birth to look at the child's future. He ignored two aspects of astrology more important to the Arabs: interrogationes and electiones. The first concerned itself with setting up a chart in order to discover the answer to a question - the identity of a thief, perhaps, or the nature of a proposed marriage. The second was a way of discovering the propitious moment for a certain action - the sailing of a vessel, the starting of a business, the consummation of a marriage.

The election of a particular moment of time was much used by doctors to discover the proper moment at which to apply medicine, perform an operation, raise a patient from bed; in a sense it is still used in the 20th century when at least some doctors choose to operate at phases of the moon when a patient is likely to bleed less freely, or a blood donor chooses to give his blood at full moon, when he bleeds more freely.

At least one Arabic work played an important part in determining the philosophical attitude to astrology held by the English church: this was the Introductorium in astronomiam of Albumasar, translated by Herman of Dalmatia who, with Robert the Englishman (Robert of Retines), travelled in Europe in the 1140s discovering astrological works.

Albumasar's work was particularly important to those concerned about astrology's relationship to free will. He claimed that while it was certainly true that some things were unarguable - fire was hot, always had been hot, and would continue to be hot - and there was no point in contention, other elements in life were mutable: he was setting pen to paper today, but might or might not continue to write tomorrow. The planets were susceptible to reason, and their powers, divinely governed, could influence both arguable and unarguable fact.

Translations of astrological books made during the 12th century were extremely influential and widely read. Some of them became profoundly popular. Bernard Silvester, who wrote in the middle of the 12th century, produced for instance three books, each dealing with astrology, which were very widely read indeed. Silvester's Experimentarius was a verse translation of a work on astrological geomancy (a means of prediction by which a number of points were dashed down at random, and then joined together by lines, creating a number of shapes then used as a key to certain constellations or sets of tables; the resident astrologer of an hotel in Agra, India, was using it still in 1982). His Mathematicus was a narrative poem based on an astrological prediction, and De mundi universitate, was about the stars themselves and their effect on the whole of creation. The latter was, in the terms of its day, a runaway bestseller, almost immediately accepted in the major schools of Europe, where interestingly there is no record of even the slightest reaction against Silvester's calling the planets 'gods' - 'gods who serve God in person' - near enough to the Creator to receive from him the secrets of the future, which they impose upon 'the lower species of the universe, by inevitable necessity'. The whole of nature derived its life from the skies, and could not move without instructions from on high - although at the same time Silvester speaks of 'what is free in the will and what is of necessity'; somewhat confusing.

The Mathematicus is perhaps the earliest work of fiction to depend entirely on astrology for its plot, which tells of a Roman knight and his lady whose marriage is childless. The wife consults an astrologer, who predicts that she will bear a son who will become a great genius and the ruler of Rome, but will one day kill his father. The wife tells the husband, who makes her promise to kill the child in infancy. Of course, when she becomes pregnant and gives birth to a son, she cannot bear to have him killed, and sends him away, assuring the husband that he is dead. The child, Patricida (so named to ensure that he will hate the crime of patricide) is intellectually brilliant, learning 'the orbits of the stars and how human fate is under the stars' and 'clasping divine Aristotle to his breast'. He grows up to be a brilliant soldier, too, rescuing Rome from the attacking Carthaginians, after which the king abdicates in his favour. His mother, understandably, is both pleased for her son and anxious for his father. She tells all to her husband, who to her dismay goes to Patricida and confesses how he had once ordered him to be killed, but had been overruled by the planets, which would no doubt one day order the king to kill his father. Patricida decides to commit suicide to save them both from fate; he summons the Romans together, induces them to promise him anything, and then announces that he wishes to die ... And here, alas, the intensely operatic poem breaks off, leaving us to construct our own version of what may have happened.

The story was written, and taken, extremely seriously; critics who suggested that it was a satire were for the most part Christian clerics intent on producing anti-astrological polemics. There is no sign in the text itself to suggest that it was anything other than a straightforward tale, and its many readers took it as such.

England produced no astrologers to compete in reputation with some of those on the Continent, although the universities taught the subject (not with as determined a conviction as that displayed at, say, the universities of Bologna or Padua). English travelling scholars brought news of the latest developments of the study into the country - among them Alexander Neckham (1157-1215), who was a foster-brother of Richard I, born on the same night as the king, and sharing his mother's breasts with his future sovereign. He grew up to be a distinguished scholar and Abbot of Cirencester, and in his book De naturis rerum wrote about astrology, astronomy and natural science in general. Richard is said to have written 'something on astrology', but the manuscript has not survived.

That the peoples of Britain as a whole were affected by astrological prognostications cannot be doubted: together with most other Europeans they were thrown into a panic, for instance, by the conjunction of planets in Libra announced for 1186. Most astrologers predicted disastrous storms (Libra is an 'air' sign), with the result that many of their more credulous listeners dug underground shelters in which to pass the crisis, and services were held in many churches in an attempt to persuade the Creator to overrule the planets.

Two English writers, Roger of Hoveden and Benedict of Peterborough, attempted to comfort their hearers by recalling that an ancient astrologer, one Corumphira, had predicted that only cities in sandy regions of the earth would be affected; but Hoveden also pointed out that an English astrologer, William, clerk to John, Constable of Chester, argued that England would be included in the area of devastation as it were by divine intervention, and that 'princes should be on their guard, to serve God and flee the devil, so the Lord may avert their imminent punishments'.

As September 1186 approached, panic spread. A tract by a Saracen astrologer, Pharamella, criticizing his western colleagues' calculations, and arguing that the positions of Mars and Venus were such as to mitigate the effects of the conjunction, was too late to comfort the superstitious. As it happened, September was a rather mild and unexceptional month, and the astrologers were forced to admit that they had been mistaken: the conjunction did not provoke storms at all - instead, it instigated the victories of Saladin in the Holy Land in the following year!

As the 12th century wore on, English astrological writers continued to consolidate ancient knowledge into accepted texts. Daniel of Morley did so under the aegis of John, Bishop of Norwich; Roger of Hereford a contemporary, under that of Gilbert Foliot, Bishop of Hereford and later of London under Henry II. Daniel wrote a book dealing very thoroughly with astrology as it affected the weather, famine or plenty, events and the history of the state, with the horoscope as it revealed the life of an individual, then with its capacity for answering particular questions, and finally with 'elections', or the choosing of a moment for a particular task. The last, of course, was of use for instance when a ship's master wanted to know an auspicious moment at which to set sail on an important voyage - astrologers had already been used for centuries to predict such moments, and would continue to be used so (even by hard-headed insurers) for centuries to come.

With the 13th century came the first really notable court astrologer since Roman times of whom we have a clear record - Michael Scot, who when he died in the 1230s was astrologer to the Holy Roman Emperor, Frederick II. There is a good anecdote about Frederick II, incidentally, who during his lifetime seems to have employed a number of astrologers. When one presented himself, he decided to set him a test, and asked, 'By what gate shall I leave the castle today?' The astrologer wrote his reply, sealed it, and told the Emperor not to open it until he was outside the castle. Frederick thereupon ordered a new exit to be made in the walls, and left through the roughly cut hole. Opening the sealed message, he read: 'The king will leave today by a new way.' The astrologer was engaged.

Scot was referred to by one contemporary as 'a scrutinizer of the stars, an augur, a soothsayer, a second Apollo'. Very little is known of the life of this Scottish scholar and astrologer, but there is extensive evidence of the way in which his mind worked - a mind crammed with curious knowledge and odd theories (that, for instance, since there are fourteen joints in the fingers of the hand - and the reasons for that conclusion are not given! - man's natural lifespan should be 140 years). He discusses in a voluminous Introduction to Astrology the theory and practice of making use of the planets to discover God's purpose for man, addressing himself to all the old quesions - how the stars are signs, not causes, and how they can be used to discover 'something of the truth concerning every body produced in this corruptible world'. He castigates 'superstitious astrologers' (those who used numerology or geomancy), though he rather enjoys describing such occult means of divination as the shapes of clouds or the appearance of the surface of liquids.

Much of Michael Scot's work is muddled and derivative, but he seems to have done some original research - on, for instance, menstruation and the phases of the Moon - and to have had a strongly felt belief that the moment of conception was, if anything, more important than the moment of birth.. A woman should always, he says, note the exact time of coitus, when she may conceive, and goes into some detail about how different positions in copulation can, with the aid of the positions of the planets, have certain results at conception.

Charming magical and superstitious omens are liberally introduced into more serious astrological theories. To discover the sex of an unborn child, ask the pregnarit woman to give you her hand. If she offers the right, the child will be a boy; if the left, a girl. If a man sneezes two or four times while engaged in business, and rises and walks about immediately, he will prosper in the undertaking; but sneeze twice in the night for three successive nights, and you forecast death or disaster.

Many stories of wizardry and magic grew up around the figure of Scot. A rhyme told of his peculiar powers:

When he stampeth his foot in Spain

The bells do ring in Notre Dame.

And people whispered of his going about by riding a demon in shape of a black horse. He is said to have foretold that he would die as the result of a blow on the head, and to avoid this always wore a steel helmet. One day, at church with the emperor, he was forced to remove it, whereupon a small stone fell on his head and killed him instantly.

Some more prominent 13th-century figures had a merely peripheral interest in astrology. But all had an interest. Albertus Magnus (1193-1280, for instance, one of the greatest scholastic philosophers of the Middle Ages, the teacher of St Thomas Aquinas, wrote little directly about astrology - yet his views on the subject come into most of his writings. Clearly, he shared the common belief that all earthly events were governed by the motions of the planets; it is asserted again and again, both obliquely and overtly. He defends free will, of course, but nevertheless asserts that a properly trained astrologer can, after studying the positions of the planets within the zodiac at the moment of birth, make predictions for the whole life of the infant - within the circumscription of what God allows. He asserts too that if an astrologer suggests a career for a boy, it will be as well to place him in it, for because of the planetary influence a special aptitude will be shown for it, as against another occupation which parents might prefer but the planets do not support. (This illustrates how astrological theory was coagulating: astrological advice about careers for children had been given before - by contemporaries of Aristotle, for instance - but was only now appearing in commentaries and textbooks.)

St Thomas Aquinas (c 1226-74), Albertus Magnus' pupil, was far less of a scientist and more of a theologian, held in high esteem by the Popes Urban IV and Clement III and canonized in 1323, less than half a century after his death, by John XXII. He took an attitude not unlike that of Albertus, denying that the stars were living beings, but claiming that no intelligent man could doubt that all natural motions of inferior bodies are caused by the movements of the planets and stars. He agreed too that many astrologers had made true predictions, if with the caveat that many others had made false ones!

Roger Bacon (1214-94), an Englishman born in in Somerset and educated at Oxford, had a troublesome relationship with the Church, being twice imprisoned for heresy. He mounted a violent attack on magic and on those who pretended to practise it; but he saw that some 'magicians' were in fact scientists seriously concerned to unravel the mysteries of existence; 'scientific magic' was permissible. But he entirely accepted astrology as explained by Albertus and Aquinas, and took much their view of it, going somewhat further than them in arguing that the planets can incline men to good or bad conduct, even if both might be modified by free will.

He spent quite a lot of time considering the planets and their connection with Christianity: the connection between Mercury and Christianity, for instance - the fact that that planet is dominant in Virgo, suggesting the Virgin, and the likeness between Mercury's eccentric orbit (then so difficult to trace) and the mysterious course of the Christian Creed. This theory was clearly expressed, and the Popes knew of it. Bacon was, in fact, a great believer in what we can only call astrological magic: he believed in the efficacy of verbal and real charms, for instance, if made under the proper planetary auspices, for they then stored up in them the strange energy of the stars and of the human spirit. He quotes a story of Moses escaping from a compromising amour with an Ethiopian princess by using a ring which caused her to forget him. And he claims that many of the miracles of the saints were performed by means of magic invocations spoken at the proper astrological moment.

The fact that astrology needed defending not against the Church but against some critics who put the word about that was anti-Christian, is underlined by the publication of a work attributed to Albertus, the Speculum astronomiae, a lengthy defence of astrology and astronony which seems to have been published round about 1277, at a time when Stephen, Bishop of Paris, and a number of clerical advisers published a condemnation of various opinions (219 of them, to be precise) attributed to 'Signor de Brabant, Boetius of Denmark, and others'. Many of these 'opinions' had to do with astrology - that (an old suggestion) the world would begin again when all the planets returned to their original positions at the time of the Creation; that 'the will and intellect are not moved in acts by themselves but by an eternal cause, namely, the heavenly bodies'; 'that by certain signs men's intentions and changes of mind are known, and whether their intentions will be achieved; and that by such figures are known the outcome of journeys, the captivity of men, their freedom from captivity, and whether they will become sages or scoundrels'; and 'that Christianity hinders science'. Whether by intention or coincidence, the Speculum astronomiae answers most of them.

There are other less important and far less talented astrological writers of the period whose names survive and whose books were read for centuries, despite often considerable inaccuracies and mistakes. John Holywood of Halifax is a case in point. He was born at Halifax, studied at Oxford, and settled in Paris in about 1230; his name was latinized as Johannes de Sacro Bosco. His fame rested on a short book, Tractatus de sphaera, which was copied and reprinted innumerable times, and printed and reprinted in several translations from the original Latin right up until 1647 - at least forty editions within a century - even after the many astronomical errors had been pointed out. It was used by Chaucer as source material for his Treatise on the astrolabe, and many distinguished scholars wrote commentaries on it.

But the most important astrological book published in Latin in the 13th century was the Liber astronomicus of Guido Bonatti, the astrologer Dante described as one of the sufferers in the fourth division of the eighth circle of the Inferno, among those spirits who in life had spent too much time trying to predict the future, and were now condemed to pace about with their heads on backwards.

Bonatti, perhaps the most famous astrologer of the 13th century, made his living by advising princes, and was for some time employed by Guido de Montefeltro. When that prince was involved in a dispute that led to military action, Bonatti would climb to the top of the campanile of his castle, and at the auspicious moment strike the bell once for the count and his men to don their armour, again for them to mount their horses, and a third time for them to ride forth to battle. Filippo Villani, a contemporary historian, claims that Montefeltro won many a battle by following his astrologer's advice.

Bonatti was absolutely forthright in his claims for his art:

All things [he said] are known to the astrologer. All that has taken place in the past, all that will happen in the future - everything is revealed to him, since he knows the effects of the heavenly motions which have been, those which are, and those which will be, and since he knows at what time they will act, and what effects they ought to produce.

His Liber astronomicus expresses the same modesty. He begins by stating that his book will be 'long and prolix', and indeed it is. He produced it after a lifetime's practical work as an astrologer - as a professor at the University of Bologna. His defence was opinionated, firm and pert - particularly where the opposition of some churchmen was concerned. Astrologers, he claimed, knew a great deal more about the stars than theologians knew about God, who preached about Him every day. Abraham had taught astrology to the Egyptians, Christ had used (or at least approved of using) astrology to choose propitious moments for certain tasks ('Are there not twelve hours in a day?' he had asked the disciples [John XI.9], obviously meaning that one could choose a fortunate time within them); and churchmen who said that astrology was neither an art nor a science were 'silly fools'.

Despite this, his book had some useful tips for ambitious clergymen; he lists various questions astrology can answer, and among them is whether an enquirer will ever attain the rank of bishop, abbot, cardinal - or even pope. This may have been a joke, although he goes on, very straight-faced, to say that while it may not be proper for a clergyman to ask such a question, many did, and an astrologer should be prepared to give an honest answer. Astrology could and should be used, too, to choose the propitious moment for starting to build a church, just as it would be when building a house or castle or city.

There remain two important European astrologers to be mentioned before the end of the century. The first, Peter of Albano, who was born in 1250, had a quiet but distinguished career. He travelled somewhat in his youth (to Sardinia and Constantinople, and allegedly to Spain, England and Scotland), spent some time at the University of Paris, where he was admired by Savanarola, then returned to Italy; was among those who met and talked to the great adventurer Marco Polo on his return from the Orient, and returned to Padua to die there in 1316, a highly paid professor.

Apart from his astrological writings, he was between 1285 and 1287 physician to Pope Honorius IV (he charged a hundred florins a day for his services, a very considerable sum), although this did not prevent him from getting into trouble with the Inquisition, which punished him after his death by disinterring him and publicly burning his bones - not because of his practice of astrology, however, but because of some unwise speculations about the raising of Lazarus (after only three days, he concluded, rather than four) and for questioning whether certain people raised from the dead by Christ and the saints might not in fact merely have been in a state of trance.

His reputation as a physician was very great, and supported by such authorities as Regiomontanus as well as by the popularity of his books on medicine. In his best-known book, the Conciliator, he lists over 200 questions which he has investigated, and after recalling the opinions of others, gives his own conclusions on medical matters. But elsewhere in the book he states a number of objections to astrology, and answers them with similar forthrightness, taking the standard view of the subject, underlining the fact that it is a science. Certainly, some astrologers might come to mistaken conclusions, sometimes because they were incompetent; but a good astrologer would speak the truth in most cases, and very rarely fail to be accurate in his prognostications.

As to medicine, which was his chief preoccupation, those who pursued it 'as they should, and who industriously study the writings of their predecessors, these grant that this science of astronomy is not only useful but absolutely essential to medicine.' All potions should be administered after a study of the planets' positions, and Peter goes into great detail about the theory of 'critical days' and their relation, especially, to the phases of the Moon. He discusses at some length whether blood-letting should take place at the first or some other quarter of the Moon. He certainly goes some way towards ascribing intelligence to the planets, describing one of them, on one occasion, as 'leading through all eternity a life most sufficient unto itself, nor ever growing old', and repeating a theory that associated certain angels with certain planets - Michael with the Sun, Raphael with Mercury, Gabriel with the Moon, and so on. However, he did not go far enough down the road to heresy to forgo the approval of the Pope, or during his lifetime to have any real difficulty with the Inquisition.

Cecco d'Ascoli, on the other hand, was to become famous as the only astrologer to be burned by the Inquisition. Practically nothing is known of his life and career; only that the two books which caused his execution were a poem, L'Acerba, and a commentary on the Sphere of Sacro Bosco. L'Ascerba is really hardly here or there - a sort of parody of Dante's Inferno; the Sphere commentary seems not in itself to be heretical. D'Ascoli affirms man's possession of free will, and offers no new or extreme astrological theories to upset the authorities. But there are one or two doubtful passages, in one of which he gives directions how the reader can make an image through which he can receive the messages of spirits (though he condemns magic).

He did from time to time refer bitingly to living people, and may well have made enemies. At all events, he was found guilty by the Inquisition at Bologna in 1324 of improper utterances, and given a fifteen day penance of confession, a daily recital of thirty paternosters and thirty Ave Marias, occasional fasting, and regular attendance at a sermon every Sunday. All his astrological books were taken from him, and he was forbidden to teach astrology, deprived permanently of his professor's chair and doctor's degree, and heavily fined.

Three years later he was again summoned before the Inquisitor - this time at Florence found to be a relapsed heretic who had violated the terms of his sentence (how, we do not know), handed over to the secular arm, and burned with his books by Lord Jacob of Brescia. Anyone found in possession either of the poem or the commentary was automatically excommunicated.

We would probably never have heard of Cecco d'Ascoli if he had not been burned; or, perhaps, he would have survived as a mere footnote in astrological history. Ironically, he does not really seem to have perished as a result of his astrological teaching or opinions, which were in no way outrageous - nor did he make such outrageous claims as that the earth was not the centre of the universe, which would have upset the Church. Perhaps most people at the time suspected that personal enemies were responsible for his fate; it was fairly obvious that it had nothing to do with astrology. After all, his astrology was that of Aquinas and Albertus Magnus, and the first had been canonized four years before d'Ascoli's pyre was lit, while the second was shortly to be beatified.

Moreover, during the 14th century astrology was all too often commemorated by ecclesiastical and lay authorities in permanent and respectable form to be anything but a recognizable part of the fabric of intellectual life. Look, for instance, at the capital of the eighteenth of the thirty-six great pillars supporting the lower storey of the Doge's palace in Venice, built in 1301. Ruskin described it as 'the most interesting and beautiful' capital he knew, 'on the whole, the finest in Europe'. The capitals are octagonal, and decorated by sixteen leaves; on the eighteenth capital are represented the planets in their houses, probably at the time when the cornerstone of the palace was laid.

Mars in Aries and Scorpio is particularly effective, showing a very ugly knight in chain mail with a scorpion in his hand, seated on a ram. Venus sits on a bull, with a mirror in her right hand and scales in her left (she rules Taurus and Libra); the Moon appears as a woman in a boat on the ocean, a crescent in her right hand, and drawing a crab (Cancer) out of the waves with her left. On the eighth side, God is represented creating man, his hand on the head of a naked youth.

I imagine the whole of this capital, the principal one of the old palace [Ruskin writes in The stones of Venice], to have been intended to signify first, the formation of the planets for the service of man upon earth; secondly, the entire subjugation of the fates and fortunes of man to the will of God, as determined from the time when the earth and stars were made, and, in fact, written in the volume of the stars themselves.

He summarized the 14th-century attitude to astrology, which was to remain constant for the next three hundred years.