Anti-magical rationalism: is reason itself a halakhic obligation, requiring the rejection of astrology, amulets, and the magical use of sancta?

Maimonides, answered from the texts and cited to the page.

The position in brief

The Torah's prohibitions on magic, divination, soothsaying, casting spells, and the magical use of sancta extend much further than the narrow halakhic tradition has supposed. One who whispers a spell over a wound while reciting a verse from the Torah, one who recites a verse over a child to save it from terror, one who places a scroll or phylacteries on an infant to induce it to sleep, are not only in the category of sorcerers and soothsayers but among those who repudiate the Torah; for they use its words to cure the body whereas these are only medicine for the soul (Hilkhot Avodah Zarah 11:12).¹

One who writes the names of angels or special shapes on a mezuzah, treating it as a protective amulet, has no share in the world to come (Hilkhot Tefillin, Mezuzah and the Torah Scroll 5:4). Astrology — the casting of horoscopes, the consulting of stars for auspicious days, the avoidance of the thirteenth floor — is forbidden Torah law, not merely cautioned against (Hilkhot Avodah Zarah 11:8-10, Letter on Astrology).

The talmudic statements that appear to endorse astrological reasoning are individual sayings of particular sages, not the prevailing law, and reason has refuted them (Letter on Astrology). A man should never cast his reason behind him, for the eyes are set in front not in the back (Letter on Astrology). Reason is, in this domain, a halakhic obligation. The community that takes my rulings seriously will uproot most of what passes for folk Jewish practice.²³

Sources

1. A person who whispers an incantation over a wound and then recites a verse from the Torah, who recites a verse over a child so that he will not become scared, or who places a Torah scroll or tefillin over a baby so that it will sleep, is considered to be a soothsayer or one who cast spells.

   Mishneh Torah, Foreign Worship and Customs of the Nations

2. Thus it has already become clear to you, you who engage in speculation, what Scripture intended in these particulars of the curses and the blessings contained in the words if the convenant, singling out them rather than the others for statement. Know likewise the extent of the great utility of this.

   Guide of the Perplexed Vol 2, p. 543

3. All the above matters are falsehood and lies with which the original idolaters deceived the gentile nations in order to lead them after them.

   Mishneh Torah, Foreign Worship and Customs of the Nations

Where the argument is made

• Mishneh Torah, Hilkhot Avodah Zarah chapter 11 (the expansion of the Torah's prohibitions on magic, divination, soothsaying, and one who casts spells)
• Hilkhot Tefillin, Mezuzah and the Torah Scroll 5:4 (writing names of angels on the mezuzah loses one his share in the world to come)
• Letter on Astrology (1191, addressed to the rabbis of Marseille, explicitly overriding talmudic astrological statements with the verified results of philosophy and science)
• Guide of the Perplexed I:61-62 (the harsh polemic against the magical use of divine names)
• Guide III:37 (reasons for the magic prohibitions)

How the argument was received

Genuinely held, articulated in the broadest possible halakhic language, and defended in the Letter on Astrology as the responsible application of reason to a tradition that has accumulated superstition. The narrow readings of Rashba and Nahmanides preserve the folk practice at the cost of the Torah's true meaning. They are not unlearned readings; they are deliberately narrow. We disagree on the substance, not on the framework. Most subsequent halakhic tradition, especially in Ashkenazi communities, has not followed my expansion. That is a fact about reception, not a fact about the truth of the rulings.