Astrology has been a topic of debate among Jews for over 2000 years. While not a Jewish practice or teaching as such, astrology made its way into Jewish thought, as can be seen in the many references to it in the Talmud. Astrological statements became accepted and worthy of debate and discussion by Torah scholars. Opinions varied: some rabbis rejected the validity of astrology; others accepted its validity but forbid practicing it; still others thought its practice to be meaningful and permitted. In modern times, as science has rejected the validity of astrology, many Jewish thinkers have similarly rejected it; though some continue to defend the pro-astrology views that were common among pre-modern Jews.
The Prophet do not accept Astrology
Jeremiah: “Thus saith the Lord: Learn not the way of the nations, And be not dismayed at the signs of heaven; For the nations are dismayed of them (Jeremiah 10:2).”
Isaiah: “Thou art wearied in the multitude of thy counsels; Let now the astrologers, the stargazers, the monthly prognosticators, stand up and save thee from the things that shall come upon thee (Isaiah 47:13
Maimonides was an exception, but he rejected astrology on theological grounds, that such belief was contrary to the doctrines of divine providence and human freewill. Among the Jewish philosophers of the Middle Ages Maimonides alone rejected astrology completely, referring to the astrologers’ beliefs as vain superstitions unworthy to be called a science.
Nahmanides, to the effect that one must not consult the astrologers but rely on God without being concerned about what the future will bring.
Judah Halevi never took a definite stand concerning the value and reliability of astrology. He admitted (Kuzari 4:9) that the celestial bodies had an influence over terrestrial affairs, that terrestrial (sublunar) life was due to the changing constellations, and that all astrological sayings attributed to the rabbis of old were based on genuine traditions. At the same time, however, he rejected the astrologers’ claim that it was possible to determine the exact influence of the stars on sublunar beings. Halevi complained that the Jewish people continued to be seduced by astrological charlatanry despite the biblical injunction to the contrary (ibid., 4:23).
The majority of Jews today are not much affected by astrological beliefs one way or the other.
Many famous Rabbis did believe in Astrology
The rabbis of the Talmud gave considerable credence to astrology. The Talmud states that “upon entry into the month of Adar one should become increasingly joyous. Rav Papa said: ‘Therefore a Jew should avoid litigation with gentiles in the month of Av, because his mazal is bad; and he should move the court case to the month of Adar, when his mazal is good.’” The Hebrew word which Talmud uses here, mazal, is usually translated “luck” but literally means “constellations.”
Abraham bar Ḥiyya based decisions in practical affairs on astrological considerations. He also undertook to prove from the Talmud that the rabbis of that time in their use of astrology agreed in principle with the gentile sages about the role played by the stars, differing only in that “they say that the power of the stars and the constellations is not a perfect power … all being at the beck and call of God, who can at will set aside their rule and abrogate their decrees whenever He desires.”
Moshe Chaim Luzzatto discusses the influence of stars on humanity and events on earth. He gave two reasons for the existence of stars and planets. The first is that stars and planets maintain the existence of all physical things on earth, acting as the means by which spiritual forces are transmitted to physical entities.
In Judaism, Astrology is not regarded as “idol worship,” even though the generic name for “idol worship” is “Avodat Kochavim U’Mazalot,” Worship of the Stars and the Signs of the Zodiac.”
From the Jewish perspective, the stars are not unrelated to events on earth. It is not irrelevant whether one was born on Pesach, or Yom Kippur, or Lag Ba’Omer or on any particular day. Each day is special and has a unique imprint.
The Sefer Yeẓirah contains several astrological passages concerning such topics as the relationship of the seven Hebrew consonants that take a dagesh to the seven planets and the seven days of the week, and the relationship of the 12 simple consonants to the 12 houses of the zodiac and the 12 months.
The Zohar takes astrology for granted and in several places employs imagery and terminology that are clearly astrological
Vestiges of Astrology in Jewish Folklore
In the Jewish religious literature of modern times there remain only vestiges of earlier astrological beliefs. On joyful occasions in individual and family life, Jews everywhere congratulate each other by saying mazzal tov (“good luck”). A successful person is popularly referred to as a bar-mazzal (“one of luck”), and a perennial failure is known as a ra-mazzal (“poor luck”; Yid., shlimazl; Aram., bish-gadda).