Rabbeinu Bahya and the Case of the Mysterious Medieval Lightning Rod

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Yaakov Taubes


It has been said that a spirit of invention has dominated American thinking since its founding. The people of the United States love to celebrate innovators and creators of new technologies, both contemporary as well as those of the past. One manifestation of this is the continued admiration and adoration of Benjamin Franklin, one of America’s founding fathers, credited with a number of useful inventions, including bifocal glasses, a new type of stove, and the urinary catheter. The invention for which he is perhaps most well-known, however, is the lightning rod.

In the early 1750s, Franklin hypothesized that lightning was itself electricity and he began experimenting to prove this. At the same time, he sought to devise a method of limiting the damage lightning caused to a building when it struck by means of placing an iron rod at its top which would cause the lightning to dissipate. Although there is no direct record of the incident and Franklin first mentioned it himself only months later, a full write up appeared in 1767 describing how Franklin, experimenting with a kite and a key during a lightning storm, proved his theory about lightning and how to prevent damage caused by it. He then began advocating for the use of lightning rods in his hometown of Philadelphia. Their use would eventually spread around the world.[1] Franklin’s experiment was immortalized in Benjamin West’s 1805 painting Franklin Drawing Electricity from the Sky, and it has become the subject of one of the most ubiquitous stories of early American innovation. Indeed, the grand story of Franklin’s invention of the lightning rod (varieties of which can still be found on houses and buildings), is taught to children until this very day.

In view of this popular story, we might be a little surprised to find a description of a lightning rod in a commentary on the Torah written in 1291! R. Bahya b. Asher,[2] (not to be confused with the earlier Bahya ibn Paquda), was a Spanish exegete who flourished in the late 13th century and early 14th century.[3] He authored Kad Ha-Kemah, an alphabetically organized encyclopedia-like work with entries on various aspect of Jewish life and beliefs, Shulhan Shel Arbah, a halakhic and mystical treatise on food and eating, and a commentary on Pirkei Avot.[4] What he is most well-known for, however, is his commentary on the Torah. The most salient feature of this commentary is, as he states in his introduction, the utilization of different methods and traditions to explain the Torah, including peshat, midrash, kabbalah, and seikhel.[5] This last method combines approaches to the text based on science, philosophy, and sometimes allegory.

Although R. Bahya typically offers more than one interpretation to explain a given idea, it is rare that we find him utilizing all four approaches in his commentary on a single verse. However, in his explanation of the story of the Tower of Babel (commenting on Genesis 11:8), specifically when he addresses what the people of that generation were trying to accomplish in their construction of the tower, he does in fact use all four. In his “al derekh ha-seikhel” approach, R. Bahya writes:

The men of the dispersion were wicked and knowledgeable in all wisdoms. They thus made a city and tower in order to be saved from a deluge of fire. Since they knew that the world had previously been destroyed in a deluge of water, they were afraid for their lives and sought to build a place such that if He [God] wanted to bring a deluge of fire and burn the world, they would be saved from it[6] … and [they would] tie up a part of the fire’s core such that it would not come close to the city. This is similar to that which we find even in our generation that some wise men know the power to tie up part of the lightning so that it will only go up to a specific boundary.

Referring to wise men who stand in a high location and are able to capture lightning and dissipate its power such that it affects a limited area sounds an awful lot like describing people who know how to use a lightning rod. Is it possible that the idea of a lightning rod was known almost five hundred years before Franklin or anyone else?

There are certainly some readers of R. Bahya’s work who thought so. A number of printed editions of R. Bahya’s commentary to this verse even insert in parentheses the word “דאננערבלייטער,“ which is Yiddish for lightning rod.[7] One can even find articles about R. Bahya that credit him with knowing the secret of lightning and how to avoid damage from it long before Benjamin Franklin or anyone else (a somewhat strange assertion since R. Bahya does not claim here that he was reflecting his own or even any uniquely Jewish knowledge, but rather that of “wise men” in his generation).[8] It seems rather unlikely, though, that these ideas were known and understood by R. Bahya in the 13th century and were subsequently lost over time. Could R. Bahya, then, be referring to something else?

 In an article published in Lechaim magazine, Arye Olman suggests that R. Bahya is referring to certain stones of power, known in the Muslim world and particularly in Persia that were said to prevent lightning strikes. Olman marshals a number of sources demonstrating that people believed that such rocks had powers and would put them in high locations for protection. Despite living in Christian Spain, R. Bahya was fluent in Arabic and certainly was aware of various aspects of Islamic culture. Additionally, R. Bahya had a strong interest in the mystical power of stones and in connection with this wrote extensively in his commentary about the stones on the breast-plate of the High Priest.[9] It is thus possible that R. Bahya is referencing a stone of power that could disperse lightning, although it is a bit difficult to read that into his commentary.

A more likely source for R. Bahya’s comment may have come from his Christian neighbors. Already in the 10th century, we have records of Christian liturgical rites that were invoked for storm protection. Similarly, a number of early Christian stories specifically describe the cross itself as providing its wearer with all kinds of protection, including from storms. Writing in the 13th century, William Durand suggests that the ringing of the church bells will not only lead people to pray for storm protection, but will also cause the demons to flee in terror, thus quieting the storm.[10] We also have records of medieval bells that were inscribed with the phrase “fulgura frango” which loosely translates as “I break up the lightning.”[11]

Interestingly, a short treatise written by the archbishop Agobard of Lyon (c. 779–840) describes the tempestarii, men and women who were widely believed to have control over storms and were able to summon or prevent them by using magical incantations. In this treatise, Agobard criticizes and dismisses these beliefs quite forcefully, although it is not entirely clear if the critique is against pagans or to counter wayward priests.[12] Regardless, the belief that magic or religious rituals could control the weather persisted far into the High Middle Ages.[13]

In time, various Christian rites, especially the ringing of church bells, may have been presented as representing the new (and true) power over storms in place of the superstitious pagan activities of mages and magicians. Church bells were of course used in many Christian rites and in some communities; they even went through a “baptism ceremony to consecrate them” for various rituals.[14] Later sources also seem to directly link bell ringing to the dissipation of storms. A 15th century book of Christian liturgical customs from Valencia, Spain (not far from where R. Bahya likely flourished),[15] for example, does not mention prayer in connection with bell ringing, but does note that one should ring the bells whenever a storm threatens, and specifies that the number of bells rung is dependent upon the severity of the storm.[16] No less a figure of science than Sir Francis Bacon, in his Sylva Sylvarum (1626), tried to explain how this functioned on a scientific level.

This idea that bell ringing could prevent or at least limit the impact of lightning thus reverberated throughout the centuries. Over the years, numerous reports addressed the efficacy of this method. There is nothing actually scientific about this approach, of course, and moreover, there are various later reports of bellringers themselves being struck by lightning while ringing during a storm. Benjamin Franklin himself, in a letter to Harvard Professor John Winthrop, wrote that lightning seems to strike the steeples of the church at the very time the bells are ringing. “One would think it was now time to try some other trick,” Franklin concluded.[17]

In R. Bahya’s time, however, bell ringing appears to have been seen as a scientific or supernatural method of dissipating storms. Could R. Bahya in our verse be referring to the ringing of church bells? Could the “wise men” who “know the power to tie up part of the lightning” refer to the bell ringers or, perhaps, some variation of Agobard’s rejected tempestarii? R. Bahya would certainly not ascribe any real power to a Christian religious ritual, but the line between magic, religion, and science was not always so clear in the medieval period. If some version of the belief in the tempestarii was still extant or if bell ringing was seen as an effective way to prevent lightning, perhaps R. Bahya is in fact referring to those who were at least perceived as being able to control its effects.

At first glance, however, one cannot help but think that R. Bahya’s description of something that catches the lightning and causes it to strike only a particular location sounds like a contemporary lightning rod. Although, as we have seen, R. Bahya may have been referring to something else entirely, the mystery might not be completely solved.

R. Bahya himself admitted that divining the meaning of matters that happened long ago can be a fraught and uncertain endeavor. After offering another explanation for what the builders of the tower of Babel were trying to achieve, R. Bahya notes that an earlier verse (Genesis 11:1) describes the generation that built the tower as having the same language and devarim ahadim. While this is usually translated as them having “the same words,” it can also be read as the Aramaic word ahid, meaning “closed.” R. Bahya goes on to explain that:

The [Biblical] verses closed the door on [understanding] the evil thoughts that they were thinking in their hearts, and did not wish to reveal what they were … While the [evil] actions of the generation of the flood was revealed to us [in the Torah], those of the generation of the dispersion were not.[18]

There is certainly an important lesson in humility to be gleaned from this. For all the different exegetical approaches and traditions that R. Bahya garnered to explain the text, he ultimately acknowledged that the motivation of the builders of the Tower of Babel remains an unsolved mystery. By the same token, perhaps we can acknowledge that despite all the wisdom we have at our disposal, R. Bahya’s lighting rod remains a mystery at the intersection of medieval science, magic, and Biblical interpretation.

Article updated October 24, 2022.

[1] For a brief description of the event and the competing claims of discovery by some of Franklin’s contemporaries, see Walter Isaacson, Benjamin Franklin: An American Life, 137-145.

[2] There is some question as to the correct pronunciation of his name. The standard scholarly is to spell and pronounce it Bahya and I have thus employed it throughout this essay.

[3] Most of his biographical background is unknown, including where he lived and whether he held any rabbinic role. Even his true name and that of his father’s is subject to doubt.

[4] These can be found in Kitve R. Bahya b. Asher, ed. C. D. Chavel (Jerusalem: 2006).

[5] R. Bahya’s approach is sometimes seen as an exemplar of PaRDeS, an acronym for peshat, remez, derush, and sod, which is used to describe the four ways of interpreting the Torah. Technical and historical issues with pardes make this assertion somewhat problematic. See Albert van der Heide, “PARDES: Methodological Reflections on the Theory of the Four Senses,” Journal of Jewish Studies 34:2 (1983): 147-159. I hope to further explore these and other issues related to R. Bahya in my forthcoming dissertation.

[6] Regarding the possibility of God destroying the world with fire, see Zevahim 116a with Shittah Mekubetzet No. 18 and Maharsha, Hiddushei Aggadot s.v. “aval”. See also Shu”t Binyan Tziyon Ha-Hadashot No. 146 who posits that there are conflicting Talmudic and Midrashic sources about this.  

[7] In the recently published Oz Ve-Hadar edition of R. Bahya’s commentary, the editors claim that this word appears in an early printed edition but do not specify which. I have looked through a number of the early printed editions, however, and have not found this insertion in any edition printed before the 20th century. Many of these editions also include a note to see Tosefta Shabbat 7:10. The Tosefta there states that placing a metal rod near a chicken coop “because of lightning” is not considered darkei ha-emori. One way of understanding this is that it is referring to a lightning rod and that placing the metal rod in the chicken coop is permitted since its effect is based on science as opposed to a kind of forbidden magic or superstition. This was indeed the understanding of some commentaries on the Tosefta, as well as Chaim Zimmerman in his Torah and Reason: Insiders and Outsiders of Torah (1979), 46-47. While such an interpretation is theoretically possible, it does not seem to be likely. A more careful read would indicate that the concern is for the negative effect that lighting was understood as having on fertility and thus the metal rod would somehow negate this and was not considered darkei ha-emori.  Shaul Lieberman, in his Tosefta Kifshuta (Shabbat 6:4) takes it as fact that the Tosefta is referring to fertility and birthing issues linked to lightning and states as much in his commentary. He also notes that the correct text should include placing a rod near a chicken coop and women in childbirth which makes it clear that the issue is not about the lightning damage we generally speak of. Indeed, there are medieval minhagim books which refer to a custom of women to have a metal knife near them during labor to protect against bad spirits (See Olman’s article cited above). Whatever the correct interpretation of the Tosefta, R. Bahya is not referring to the Tosefta since he attributes this idea to the wise men of his generation, and not the Tosefta, which he quotes in other places.

[8] See Encyclopedia le-Toldot Gedolei Yisrael, Volume I, ed. Mordechai Margalioth (Jerusalem: 1946), 257.

[9] See Samuel Kottek, “Precious Stones in Jewish and Christian Medieval Literature: Natural and/or Occult Sciences?” Korot 16 (2002):89-110.

[10] See James Monti, A Sense of the Sacred: Roman Catholic Worship in the Middle Ages (San Francisco: 2012), 632-638. A number of later sources (including Isaacson) have cited Thomas Aquinas as writing about the efficacy of bell ringing in dissipating storms, but no original source has been provided.

[11] See here for a picture of such a bell from Germany (now in Switzerland) cast in 1486.

[12] Rob Meens, “Thunder over Lyon: Agobard, the Tempestarii and Christianity,” in Paganism in the Middle Ages: Threat and Fascination, eds. C. Steel, J. Marenbon, W. Verbeke (Leuven: 2012), 157-166.

[13] See, for example, James George Frazer, The Golden Bough: A New Abridgement (Oxford: 1998), 736-744.

[14] See H. Thurston, “Bells,” in The Catholic Encyclopedia. (New York: 1907).

[15] As referenced above, it is not entirely clear where in Christian Spain R. Bahya resided. Although he is commonly thought to have lived in Saragossa, definitive evidence for this is somewhat lacking.

[16] Cited in Monti, A Sense of the Sacred, 635.  

[17] Isaacson, 138.

[18] This is loosely based on Midrash Bereishit Rabbah 38:6.

Yaakov Taubes is the rabbi at Mount Sinai Jewish Center in Washington Heights, New York. He also serves as an assistant director at the Rabbi Isaac Elchanan Theological Seminary at Yeshiva University, and is a PhD candidate in Medieval Jewish History at the Bernard Revel Graduate School for Jewish Studies. He can be reached at