From Moezzi’s book The Divine Guide in Early Shiism:
There is also astrology (al-nujtim); the efficiency of this divinatory “art” is recognized by the imams. Mu‘all'a b. Khunays412 asks Ja‘far whether astrol ogy istrue, to which the imam replies affirmatively.513 In a conversation about astrological calculations, the same imam states: “ ...This calculation is actu ally true, but only he who has the Knowledge of the horoscope of allcreatures [that is, the imam] can know it.”514 And Ja‘far al-Sadiq also says: “Only one family from among the Arabs [ahl baytin min al-‘arab—that is, the family of the Prophet, the imams] and one family from among the Hindus [ahl baytin min al-hind] know the Science of astrology.”515 ‘Abd al-Rahman b. Siyaba516 says to Ja‘far: “People [al-na‘s, that is, the Sunnites] have said that astrology is illicit,butIam attractedtoit;isitprejudicialtomy religion?Ifso,Iwillgive upmy study,butifthisisnotthecase,Iwishtolearnit.”Theimamreplies, “It is not as they say; astrology does no harm to religion. However, you are studying something about which you know very little, and the least amount that you grasp will do you no good, since your calculations are based only on the trajectory [MW] of the moon; do you know how many minutes there are between Jupiter [aI-mushtari] and Venus [al~zuhra]?” “No.” “How many minutes there are between Venus and the moon? Between the sun and Virgo [al-sunbula]? . B.etw.een Virgo and the Well-Guarded Tablet [al-lawh al mahfuzl?” “No, for heaven’s sake, for no astrologist has spoken of these things.” “In each case there are 70 minutes. ‘Abd al-Rahman, who knows thesecalculationsthoroughly,couldtellyouexactlyhowmanyreedsthereare in a field of rushes.”5'8
There are, however, other statements where the imams appear to wish to warn their disciples against purely magical applications of astrology, astrol ogy that has been “profaned,” separated from a Science that has been acquired through divine intervention, since it would otherwise tend toward “black magic.” ‘Ali says: “0 people [ayyuha l-nas, although we are not sure whether he is speaking with disciples or with “ordinary” people], beware of learning astrology, except where itassists you in finding your way over land or sea.519 Astrology leads you to divination; the astrologist is like the diviner, the diviner like the magician, the magician like the impious, and the impious are destined for Fire. Undertake your actions [by relying] on the Name of God.”520 Elsewhere the same imam, after rejecting the predictions of an astrologist,finisheshisstatementwiththewords“MyGod,thereisnodivina tion other than Your divination [al-tayr, lit. “omithomancy,” although the word here means techniques of divination in general, including astrology], there is no bad omen other than Your bad omen, there is no good omen other than Your good omen, and no god other than You.”52l