Maimonides and Nahmanides had their differences.
Maimonides (d. 1204) tolerated no idea that failed the test of reason. An ancient and robust tradition of superstition among the Jews did not deter him. Maimonides either ignored or rationalized scores of Talmudic halachot based on astrology, demonology, and magic.
Maimonides denounced astrology passionately, despite its popularity, calling the belief “stupidity” and its practitioners “fools.” His argument bears emphasis: Maimonides opposed astrology primarily on scientific rather than religious grounds. The Torah prohibits divination from the sky, he ruled, not because it displays a lack of faith in God, but simply because it is false.
But Nahmanides (d. 1270), pointing to Talmudic sources and consistent with his intellectual milieu, wrote a correspondent that it would be halachically unacceptable to ignore an inauspicious horoscope, because “one should not rely on miracles.”
Though a student of Kabbalah, Nahmanides also worked within the framework of Aristotelian philosophy. He was no anti-rationalist. He was worlds apart from today’s magic-remedy-dispensing “mekubalim” (miracle workers).
Medieval philosophers relied on reason to explain nature, but reason had practical limitations. Even the most confident rationalist could not explain all natural phenomena. Philosophers were forced to distinguish between “manifest” qualities — clearly understood properties such as size, shape, and color — and an “occult” or hidden property unique to a particular object (“segula” in medieval philosophical Hebrew).
The attractive force of the lodestone, a naturally occurring magnet, was the most commonly cited example of an occult quality.
The ancients knew that a magnet draws iron, but the cause of the attraction eluded explanation. Medieval scholastics viewed such “action at a distance” as an occult property; no manifest quality of the lodestone could explain its power. Likewise, the stars and planets were thought to influence the daily affairs of human life by means of emanations penetrating the cosmos — an even more impressive example of action at a distance.
Occult remedies were a problem for halachists and Jewish philosophers. The issue came into sharp focus in the early fourteenth century, during the Maimonidean Controversy. Rabbi Shlomo Ben Aderet (“Rashba,” d. 1310), a student of Nahmanides, played a major role in this episode. Like many of his contemporaries, Rashba revered both Maimonides and Nahmanides.
Rashba was asked for his decision: Was it permissible to use a medallion engraved with the image of a lion — after the zodiac constellation Leo — to treat kidney stones? (Ironically, the radical Maimonidean rationalists were using this talisman; the anti-Maimonideans objected).
Rashba deliberates carefully, and takes great pains to address Maimonides’ broad prohibition of magic. He notes that Maimonides himself, following the Talmud, allowed for an exception: He permitted any empirically effective remedy, even if it was poorly understood and attributed to an occult virtue. Does this exception, Rashba wonders, cover the Leo medallion?
Rashba ultimately allows the practice. He skillfully argues that the medallion’s healing property, though occult, is as natural as magnetism (the following is the earliest description of a magnetic compass in Hebrew literature):
“Consider the occult property of the magnet, at which iron leaps, and furthermore, the common practice of sailors: They insert a needle into a floating piece of wood and magnetize the needle, which navigates on the water’s surface until it points to the pole. Not a single philosopher comprehends this in terms of natural philosophy. Likewise, all occult properties are natural — in the manner of drugs and herbs — and include no element of paganism.”
This chapter in the history of three intersecting fields — philosophy, science, and halacha — remains relevant today. How should a modern traditional Jew respond to magical cures, astrology, and the variety of “segulot” (talismans, in its current usage) increasingly promoted by Jewish charismatics?
We may be tempted to fall back on the old debate between Maimonides and Nahmanides and decline to take a stand. It would be presumptuous, so the argument goes, to come down on either side.
But there is a better approach, which takes historical context into account. An example from another area of halacha may help disentangle the issue.
Centuries ago, several prominent halachists permitted smoking on non-Sabbath holidays, based on its presumed health benefits. The rationale was that smoking fell into the halachic category of kindling for a universally appreciated pleasure (e.g., a healthful activity), which is permitted on holidays.
No halachist today would tout the health benefits of smoking simply because this (erroneous) idea is part of the halachic record. Thankfully, scientific progress makes such a prospect laughable.
Needless to say, science has evolved considerably since the fourteenth century: The Renaissance, Copernicus, Galileo, Newton, and the Enlightenment; not to mention Darwin and Einstein.
We have known for some time that magnetism is not an occult force. We also know that astrology is a pseudoscientific fantasy (on this score, Maimonides was far ahead of his time). Much of what was fact to the medievals may be of interest to historians of science, but is no longer scientific reality.
Nahmanides and Rashba were no fools. If they were active today, they no doubt would mock practitioners of magical cures and those who would read fortunes from molten lead or coffee grinds. Maimonides likewise would abandon his own outdated science.
On scientific questions, religion must follow the very latest science. To settle for anything less is to invite a return to a darker, occult age.