Astrology

As a means of divination, astrology is rarely mentioned in Celtic myth. Yet Pomponius Mela (ca. a.d. 43) referred to the high regard in which the druids were held for their “speculations by the stars.” Flavius Magnus Aurelius Cassidorus (ca. a.d. 490–583), mentions a certain Celtic tribe, the Getae, as being learned in natural and moral philosophy and knowing the “course of the twelve signs of the zodiac, and of the planets passing through them and of the whole of astronomy.” The Sicilian Greek, Strabo (64 b.c.–a.d. 24), spoke of a Celtic druid named Abaris in Athens discussing such matters with the Greeks. At a time when astronomy and astrology were the same science, the Celts were, according to Cicero, Caesar, Pliny, Tacitus, and other classical writers, masters of astronomy.

In Whitley Stokes’ study Three Homilies we find contemporary reference to St. Colmcille casting a horoscope to determine the best time for his foster son to commence his education. By the tenth century a.d., the Saltair na Rann (Psalter of Quatrains), composed at the end of that century, states clearly that every educated person in Ireland had to know the signs of the zodiac with their names, in order, and the correct month and day when the sun entered each sign. The Saltair na Rann is one of the primary indications of the widespread knowledge of astrology in Ireland at this time. Indeed, according to Cormac Mac Cuileannain (a.d. 836–908), writing in Sanas Chormaic (Cormac’s Glossary), it is stated that all intelligent people could estimate the hour of the night throughout the year by studying the position of the moon and stars. In Welsh tradition, in Hanes Taliesin, Taliesin is claimed as an astrologer, among his other talents.

Why the neglect of astrology in Celtic mythology when the evidence of its everyday use from an early period is clear? We have Cathbad casting a horoscope for Deirdre at her birth. But we find other forms of divination widely practised in Celtic society. Could astrology have been frowned on by Christianity? Certainly Fergal, from Aghaboe, Co. Laois, who became St. Virgil of Salzburg, was admonished by Pope Zacharias (a.d. 741–752) at the behest of St. Boniface for his “cosmographical speculations.” But Christianity tended to embrace astrology as a science until the seventeenth century (“The Age of Reason”). One of the most famous of Irish