Jewish astrology () is the system of belief in some forms of Judaism that celestial bodies can influence the affairs of Earth and life thereon. Jewish astrology involves the study of the celestial bodies' respective 'energies' based on recurring patterns that change by the hour, by the week, month, year, or by several years (time categories). In each of these time categories one of the seven planetary spheres, or what are known as the seven classical planets: the Sun, Venus, Mercury, the Moon, Saturn, Jupiter, or Mars, along with the month's current Zodiac constellation, come into play and influence the sublunary world. At times, it involves a complex combination of several of these factors working together. In Judaism, this belief is expressed by the affirmation in Job 38:33: "Do you know the laws of Heaven; Or impose its authority on Earth?" From the biblical text, Rabbi Shimon ben Pazi, an , is recorded in the midrashic text Genesis Rabbah 10:6 teaching, "There is not a single blade of grass that does not have a constellation in the firmament that strikes it and says to it: 'Grow.
Complementary to the records of past civilisations, the corpus of Jewish literature has preserved many of the details instructive of the determining factors involved in rendering any astrological forecast, although astrology, in terms of modern science, is understood to be a pseudoscience.
Rabbinic belief
A famous meme that underscores the importance with which Judaism views the influences of the horoscope is found in the Idra of the Zohar:Book of the Zohar, vol. 3, section 134a
In the Babylonian Talmud, a controversy is presented among the sages of Israel as to whether the changing signs of the zodiac affect a person's destiny. The supportive opinions are of Joshua ben Levi, who lists the types of people according to their various zodiac signs, and of Hanina bar Hama, who believes that the astrological constellations (mazzal) can make a person wise and can even make a person wealthy. Conversely, Johanan bar Nappaha held the view that "Israel is not bound by the effects of the changing horoscopes."Babylonian Talmud (Shabbat 156a) He assayed to bring proof from a verse taken from the prophet Jeremiah: "Learn not the way of the nations, nor be dismayed at the signs of the heavens because the nations are dismayed at them."
The opinions of Abba Arikha, of Samuel of Nehardea and of Rabbi Akiva, however, seem to be supportive of applied astrology, even though the people of Israel are not bound by the influences of the constellations. Other rabbis have vaunted their knowledge of applied astrology. Said Samuel of Nehardea, "I know the pathways of heaven as I do the pathways of Nehardea, excepting the comet, about which I know nothing."Babylonian Talmud (Berakhot 58b)
In several places in the Talmud it is stated that every man has a celestial body (mazzal), i.e. a particular star which is his patron from conception and birth (Shabbat 53b; Baba Kama 2b) and which perceives things unknown to the man himself (Megillah 3a; Sanhedrin 94a). Two people born under the same star are also said to have a bodily and spiritual kinship (Nedarim 39b; Baba Metzia 30b).
Rava says, "Duration of life, progeny, and subsistence are dependent upon the constellations."Babylonian Talmud (Moed Katan 28a)
The great men of Israel in the Middle Ages, viz., Saadia Gaon, in his commentary on the Sefer Yetzirah; Solomon ibn Gabirol in his Keter Malkhut, and Abraham bar Hiyya, ha-Nasi and Abraham ibn Ezra considered astrology to be true wisdom and even expressed this belief in their works.Abraham ibn Ezra once wrote, "The orb and constellations of the Zodiac are in their stations. / They have inclined in their circuit because of my nativity. // I have wearied myself to become successful, but to no avail, / for the stars of my heavens have dealt perversely with me!" [Original Hebrew: ]. Judah Halevi also acknowledges in his magnum opus, the Kuzari, that the celestial bodies have an influence on earthly affairs, but does not admit that the astrologers have the ability to determine the mode of operation of the star systems on human beings and other living creatures in the terrestrial world.
Maimonides, who lived in the late twelfth century, took a more critical approach to the topic of astrology, ruling that man was entirely incapable of foretelling futurities by observing the celestial bodies, especially if those same astrological formulae were faulty. He, therefore, cancelled its practice altogether. Among the rabbis of the Middle Ages, Maimonides was the sole antagonist of such practices. One of his contemporaries and disputants, Abraham ben David, in his glosses to Maimonides' Mishneh Torah (Hil. Teshuvah 5:5), asserts the influence of the stars upon destiny, while contending that by faith in God man may overcome this influence.Marcus Jastrow, Ludwig Blau, Kaufmann Kohler (eds.), "Astrology," in: The Jewish Encyclopedia (1906)
Moshe Chaim Luzzatto, during the Age of Enlightenment and although never actually having used his knowledge of the occult to foretell futurities, speaks about the influences of the stars in his book, Derekh Hashem (II, chapter 7 – The Influence of Stars).
Proscription against idolatry The rabbis have distinguished between gaining an occult knowledge of the stars' influences on human beings (which is permitted) and the actual worshipping of the stars (which is prohibited), a view that is also met with the Scripture; cf. [the stars and all the host of heaven] "which the Lord thy God hath divided unto all nations" (Deut. 4:19), that is to say, the stars, which God appointed to be the means of governing His creatures, and not the objects of man's worship.Cf. Rabbi David Kimchi's comment (RADAK) on Jeremiah 10:2.
The Midrash HaGadol (on Deuteronomy 4:19) clarifies what is meant by, "[And beware] lest you raise your eyes to heaven, etc." It is hereby inferred that you are not to say, 'since these stars and constellations govern the world, and they provide light unto the entire universe, and they serve before their Creator on High, it is fitting that we serve them and bow down unto them, just as the king would want [all] human beings to behave with respect towards his servants and ministers.' For this reason it says, lest you raise your eyes to heaven, beware that you do not err in this manner, on account of what [is written], which the Lord thy God hath divided unto all nations. They (i.e. the astrological horoscopes) have been delivered into the hands of the nations, so that they may live [thereby] and their beings be sustained [thereby], [without] suffering loss, as is the custom of the world. But you (i.e. the nation of Israel) have been given over to me, and I do not behave towards you as is customarily practised with all the world, as it says, But the Lord has taken you (Deut. 4:20), etc. Likewise he says, Learn not the way of the nations, nor be dismayed at the signs of the heavens; for the gentiles are dismayed at them (Jer. 10:2). The nations of the world are alarmed by them, but Israel is not alarmed by them."
A similar theme is found in other rabbinic literature concerning Abraham the patriarch, who, although wise in the astrological sciences, and who saw thereby that he would not beget any children, was reprimanded by God who said to him: "Break away from your astrological speculations, for [the people of] Israel are not bound by the influences of the horoscope."Babylonian Talmud (Nedarim 32a; Shabbat 156a); Rashi on Genesis 15:5 By this Rashi learnt that through prayers, repentance and meritorious deeds (sometimes also through a change of name), they are able to alter what has been determined for them.Babylonian Talmud (Shabbat 156a, Rashi's commentary, s.v. )
The people of Israel are prohibited by Jewish law to consult the astrologers and star-gazers for guidance, but are commanded to be perfectThe Hebrew word used in Deuteronomy 18:13 is , which is translated by Onkelos as , = "perfect," but which word has also the connotation of being "naïve", based on Rabbi Saadia Gaon's Judeo-Arabic translation of the same word ( = ) in their awe of God and to consult him for guidance, even when they are told by astrologers what might happen.Nachmanides, on Deuteronomy 18:13 (P. Shoftim), p. 74
Astral influences and how they are determined The day is divided into 12 equal hours. The night, likewise, is divided into 12 equal hours. In both cases, the method of configuration used in measuring the hour is known as the Relative hour. To determine the length of each relative hour, one needs but simply know two variables: (a) the precise time of sunrise, and (b) the precise time of sunset. Although in Talmudic literature one begins to reckon the beginning of a day some 72 minutes before sunrise and where each day ends 13½ minutes after the sun has already set, here, in the case of astrological computations, it was only necessary to reckon the day from the moment of sunrise. Rashi, however, alludes to the day beginning at dawn ().Babylonian Talmud (Berakhot 59b, Rashi s.v. ). By collecting the total number of minutes in any given day (from daylight hours) and dividing the total number of minutes by 12, the quotient that one is left with is the number of minutes to each hour. In summer months, when the days are long, the length of each hour during daytime can be as much as 77 minutes or more, whereas the length of each hour during nighttime can be less than 42 minutes.
To each hour of the day and night is assigned one of the seven planets or spheres, which same planet governs the world during that hour. The names of these planets are: Saturn (shabtai), Venus (nogah), Jupiter (tzedek), Mercury (kokhav), Mars (ma'adim), Moon (levanah) and the Sun (ḥamah). [Note: The ancients conceived that there were only seven primary planets. The moon, although a satellite rather than a planet, was also numbered among them; the sun, which is a star rather than a planet, was also numbered among them. The earth was not numbered among them since it was central to the rest. Uranus, Neptune and Pluto, as well as the other recently discovered planets and satellites, were not known to the ancients, and therefore are considered trivial to the rest]. The star or planet that begins the first diurnal hour of a particular weekday, or the first nocturnal hour of a particular weeknight, it is the same star or planet that broadly governs that entire day or night.Adani (1997), chapter 17 (Introduction)
Number Lunar month Zodiac (Hebrew) Zodiac (Latin) No. of days Composition 1 Nisan , (ṭaleh) Aries (nature: fire)Adani (1997), 97b 30 days represented by 13 starsAdani (1997), chapter 17 (p. 93a) 2 Iyar , (shor) Taurus (nature: earth) 29 days represented by 33 stars 3 Sivan , (te’umim) Gemini (nature: wind) 30 days represented by 18 stars 4 Tammuz , (sarṭan) Cancer (nature: water) 29 days represented by 9 stars 5 Av , (arieh) Leo (nature: fire) 30 days represented by 60 stars 6 Elul , (betulah) Virgo (nature: earth) 29 days represented by 25 stars 7 Tishri , (moznayim) Libra (nature: wind) 30 days represented by 8 stars 8 Cheshvan , (ʻaḳrab) Scorpio (nature: water) 29 days represented by 21 stars 9 Kislev , (ḳeshet) Sagittarius (nature: fire) 30 days represented by 31 stars 10 Tevet , (ğedi) Capricorn (nature: earth) 29 days represented by 28 stars 11 Shevat , (deli) Aquarius (nature: wind) 30 days represented by 42 stars 12 Adar , (dagim) Pisces (nature: water) 29 days represented by 34 stars The observance and reckoning of the movements of the 12 constellations are believed by some scholars to have been learnt from Hellenistic culture, after first being divested of influences that were deemed idolatrous.