Q. Abraham is promised progeny as numerous as the stars. How does Judaism regard star-gazing and astrology?
A. Ben Sira says in the Apocrypha, “The beauty and glory of heaven are the stars, gleaming ornaments in the heights of God. At the word of the Holy One they take their prescribed places and they sleep not at their watches” (Ecclesiasticus 43:9).
But there are divergent views as to whether the stars and heavenly bodies influence events in the universe. The Song of Deborah declares, “The stars in their courses fought against Sisera” (Judges 5:20); but this was no mere astrological superstition, as the Century Bible points out in its comment, “The heavenly bodies that rule the seasons and weather helped the Hebrew against Sisera by flooding the Kishon”.
However, the less rational approach was hard to shake off. There is a legend that Abraham had a diagram that charted the power of the stars, but when told to abandon astrological calculations he complied. The simple people were harder to convince and were reluctant to question the influence of the stars, though one prophet after another trenchantly condemned it. Divination came under attack by Hosea, Amos, Micah and others. Isaiah scorned “the astrologers, the star-gazers, the monthly prognosticators” (Isaiah 47:13). Jeremiah insists on the absurdity of being influenced by “the signs of heaven” (Jer. 10:2).
Yet astrology become entrenched regardless; Josephus says it was widespread in his day, and even Talmudic sages took it seriously. The great Rava said that “Life, merit and sustenance depend not on merit but on the stars” (Mo’ed Katan 28a), though Rabbi Akiva, Rabbi Yochanan and others declared that the stars had no power over the destiny of Israel (Shabbat 156a, etc.).
A number of great medieval thinkers regarded astrology as a respectable science, though Maimonides unambiguously rejected and condemned it. However, many later writers took no notice of him, and the Zohar says, “There is not one blade of grass in the whole world over which a star or planet does not preside” (2:171d).
To the modern mind it is difficult to ascribe credibility to astrology, but there are presumably Jews amongst the eager readers of the astrological columns. Simplistic popular superstitions are hard to shake, even the habit of saying mazal tov, which is literally, “May you have a good planet”. The only way one can say mazal tov without being superstitious is to regard mazal as the initial letters of “Makom, Z’man, La’asot“, i.e. be in the right place (makom) at the right time (z’man), and you can achieve something (la’asot). This is an acknowledgement of historical forces, not an assertion of mere heavenly co-incidence.