Unpacking the Iggerot: Pure Passengers & Complicated Cargo
Read more about “Unpacking the Iggerot” and see the archive of all past columns.
Meit on a Plane / Iggerot Moshe, Y.D., vol. 2, #164
Summarizing the Iggerot
R. Moshe Feinstein was not just America’s posek. He received questions from across the globe, and in the case of one 1972 query, from a young man named Yitzchak Pollack of Belgium. The inquirer was concerned that families seeking to transport their dearly departed for burial in Eretz Yisrael, despite noble intentions, had unwittingly introduced a stumbling block for any kohanim who wished to fly on those same airplanes. (According to most reports over 65% of El-Al flights from New York are transporting bodies for burial in Israel; however, the issue of human remains on board a flight is relevant to kohanim no matter which airline or destination is involved.)
While the cargo (including coffins) is stored separately from the passengers’ compartment, the physical barrier would prove to be an ineffective halakhic interposition between the two cabins. Metal is susceptible to tuma (ritual impurity), and anything which can itself become impure cannot impede its spread.
R. Feinstein, however, raises the possibility that not all metals are created equal. The Torah specifies only six kinds of metals: Gold, silver, copper, iron, tin, and lead (Numbers 31:22; we will leave the debate over precise definitions aside). While ostensibly only these six are mentioned because they were the common metals known to the ancient Israelites, he views them as a specific choice by the Torah, to the exclusion of all other metals. R. Feinstein reasons that an eternal and omniscient God would know that more classifications of metals existed and would ultimately be discovered. Therefore, if the Torah only mentioned these metals it was because only they constitute metal for halakhic purposes, such as the laws of ritual purity.
It follows that if one could ascertain that the metal used in constructing the airplane, or majority of the composite, does not contain one of the six metals listed in the Torah, there would be an effective halakhic barrier interposing between the cargo and the passenger compartments, thereby protecting and enabling kohanim to fly without fear of halakhic repercussions.
At the end of the responsum, R. Feinstein raises another possible ground for leniency. Similar to our column on R. Feinstein’s responsa on kohanim entering hospitals, the concern is that tuma is being transported via the roof or “tent” which is shared by both the cadaver and the kohen. He notes that since the airplane would be in motion it could be classified as an ohel zaruk, a “thrown tent”; such a mobile structure does not constitute a “tent” for halakhic purposes.
R. Feinstein, however, did not deem it necessary to delve deeply into the intricacies of the matter. The proposed solution of classifying an airplane as an ohel zaruk never gets off the ground (pardon the pun), since both the kohen and the corpse must board the plane while it is still motionless prior to take-off. For a short, yet certainly significant amount of time, the plane will constitute an absolute ohel. Therefore, the only recourse that R. Feinstein offers for kohanim to take a plane to Israel with a corpse aboard is his first solution: the leniency that planes are not primarily composed of one of the six Biblical metals (aluminum makes up the majority of modern commercial airliners). As such, the kohen would not be impacted by the tuma beneath.
Connecting the Iggerot
R. Feinstein’s responsum on whether kohanim may travel via an airplane to Israel has far wider implications than the immediate issue at hand. In theory, it touches on a fundamental question of how halakha should approach new realities that were previously unknown—even unimaginable. In the above responsum, R. Feinstein assumed “innocent until proven guilty,” so to speak. He reasoned that if the Torah did not address a particular kind of metal we are safe to assume it is not susceptible to contracting tuma.
However, this approach appears to be contradicted by R. Feinstein’s 1960 responsum to his noted disciple, R. Ephraim Greenblatt (O.H., vol. 2, #92). In this piece, R. Feinstein rules that a rubber developed by purely chemical means is “a new entity that was unknown to earlier generations” and therefore may not be kashered. In this case, R. Feinstein was faced with a new material, just like in the case of tuma on airplanes. Yet here, he takes the opposite approach and sides with stringency, arguing that in the absence of precedent our default is that we are unable to kasher such utensils. In other words: “guilty until proven innocent.”
A potential reconciliation of these seemingly contradictory opinions can be gleaned from yet another esteemed disciple, R. Shimon Eider, who suggests in his book (Halachos of Pesach, ch. 13, fn. 10) that R. Feinstein only forbade kashering the rubber utensil out of caution in the case of the stringent laws of Passover. Under this framework, R. Feinstein’s lenient ruling on non-Biblical metals is the norm, while his cautious approach to rubber on Passover is the exception. Accordingly, in the absence of precedent we may generally assume leniency.
However, there is a more immediate answer that can be located within R. Feinstein’s initial responsum on airplanes. We need not go further than the Talmud itself which already recognized that the laws of ritual impurity is a category unto its own, regulated by their own, sometimes distinct, principles (Yevamot 103b). It can be fraught to attempt a logical extrapolation from the laws of tuma and tahara to other areas of halakha, and vice versa. If the Torah only specified six kinds of metals, it is yet another inexplicable aspect of this enigmatic area of Biblical Jewish law.
Challenges to the Iggerot
With this in mind, we could perhaps posit the opposite theory. Perhaps the responsum against kashering rubber is the rule while the lenient opinion classifying non-Biblical metals is the exception. Perhaps in the absence of precedent R. Feinstein would have us opt for the more cautious route?
The opposition to R. Feinstein’s responsum is quite straightforward. He posited that the Torah provided an exclusive list of only six bona fide Torah metals. Anything else would not constitute a metal for halakhic purposes and requirements. Virtually all who question R. Feinstein’s claim, such as R. Naftali Frankel (Moriah: Yarhon Torani le-Divrei Halakha u-Mahashava [I Adar 5744], 75-77), cite the author of Tifferet Yisrael, R. Yisrael Lifschitz (1782–1860), in his introduction to Taharot (no. 44), who views the six Biblical metals as examples rather than an exhaustive list. Instead of seeing them as exclusive, R. Lifschitz understood that there is a common denominator that these six metals share; any material that resembles them in requiring a blacksmith’s forge, hammer and anvil, constitutes a metal for all Torah purposes and resultant ramifications. Accordingly, even if the hull of a plane is comprised of post-Biblical metals (aluminum was only first produced in 1824), it would still be vulnerable to tuma, thereby exposing the kohen above.
R. Feinstein makes the same claim about Biblical metals vis-a-vis the laws of immersing vessels (Y.D., vol. 3, #22). (While he does concede that there is a Rabbinic requirement to immerse non-Biblical metals, such as aluminum, he maintains the same theory on a Biblical level.) As we have noted in other columns, rather than challenge the posek ha-dor head on, some attempt to reframe R. Feinstein’s rulings, rather than refute them. Sefer Taharat ha-Kohanim (pp. 194-195) reports: “And I heard from R. Dovid Feisntein shlit”a, son of the Iggerot Moshe zt”l, that his father did not rely on this reasoning [to permit kohanim traveling on planes] to be lenient in practice. [Rather,] he wrote it for purely ‘academic’ purposes.”
We should note that this is a tough pill to swallow. It is one matter to claim that a Talmudic discourse in Dibberot Moshe was reserved for the halls of Mesivta Tifereth Jerusalem and the type of speculative arguments (svara) we are accustomed to hear in the beit midrash. It is quite another matter to believe that R. Feinstein provided “speculative guesswork” in place of concrete guidance to an individual requesting a practical ruling. Regrettably, R. Dovid Feinstein has already departed to the next world and this account cannot be corroborated.
R. Moshe Sternbuch addresses R. Feinstein’s central claim about Biblical metals across several of his own responsa. In Teshuvot ve-Hanhagot (vol. 3, #337) he ups the ante by noting that this entire discussion does not just apply to the kohen traveling, but to the families who would send their deceased on these planes and thereby create a spiritual stumbling block for priestly passengers.
With that being said, he rules in a separate responsum (Teshuvot ve-Hanhagot, vol. 1, #678; cf. #451, where he reports the opinions of Hazon Ish and R. Yaakov Kamenetsky) that it is incumbent upon each kohen to investigate which flights are designated to carry caskets before booking a flight. R. Shternbuch adds that even if the majority of planes do not carry a corpse, the kohen must ascertain the status of his flight and not rely on the majority. He explains that while in cases of doubt halakha generally permits reliance on majority occurrences, a doubt that can actually be clarified is no true doubt.
[El-AL recently announced “Coffin Free” daily flights from JFK.]
R. Shternbuch does, however, note the possibility of encasing caskets with materials such as plastic. Should the proper dimensions be adhered to, it could theoretically obviate any concerns of tuma without the need to rely on R. Feinstein’s novel theory of non-Biblical metals. Adopting such a method would render R. Feinstein’s novel leniency moot and thereby settle the entire controversy before (here we go again) it takes flight.
Reflecting on the Iggerot
As the Torah was revealed by the omniscient and eternal God, its principles and dictates are objective and everlasting. In more recent times, we have had to revise our understanding of previously-held scientific truths, whether it be the spontaneous generation of lice or the ancient Greek belief in the four elements. However it was never the essence of the halakha that changed, but simply its application to our updated understanding of reality. The discovery and creation of numerous new metals is yet another data point within the broader question about how halakha reacts to new scientific data. And, as demonstrated above, it could serve as a case study in how rabbinic authorities approach unknowns—do we “assume innocent until proven guilty” (akin to lo rainu aino raya) or is it better to err on the side of caution?
Subsequent to an oral presentation of this topic, an esteemed member of my community, Mr. Michael Alexander, noted that perhaps R. Feinstein’s responsum on peanuts is pertinent to this matter (O.H., vol. 3, #63). R. Feinstein rejects the idea that peanuts should constitute kitniyot and thereby be forbidden to Ashkenazim on Pesach. Ostensibly, it is similar to his lenient ruling regarding newly discovered metals—if it has no precedent, we may assume it is permissible. However, a key factor noted by R. Feinstein, is that the permissibility of peanuts hinges on a technicality in the laws of minhagim, or communal custom. Even if peanuts share a similar risk for being mixed with grain, as other legumes, since the early adopters of the ban on kitniyot never had the opportunity to deliberately abstain from peanuts it was simply never incorporated into its strictures.
We should note that there can be many reasons why one may opt for a lenient or stringent path in any given scenario. On the most basic level, a Biblical doubt requires erring to the side of caution, while a Rabbinical-level doubt permits a lenient approach. While there are exceptions, perhaps we can detect a pattern throughout R. Feinstein’s responsa that even though he did not shy away from dispensing a stringent ruling, he was often sensitive to not impose a needless burden on his broad, global constituency. (A case in point can be found in a brief responsum from the end of his life in 1985, in which he refuses to espouse a stringent position on insect inspections that was not practiced by earlier generations—see Y.D., vol. 4, #2).
Indeed, it can be inferred from this remarkable responsum that the young man from Belgium hopefully took the newly-found halakhic opportunity to visit Israel, even as a kohen.
Endnote: For more opinions on the question of kohanim flying on planes that are transporting coffins, see Responsa Shevet ha-Levi (vol. 9, #251); Responsa Helkat Yaakov (Yoreh De’ah, #213); R. Hershel Schachter, Be-Ikvei ha-Tzon (p. 232); Petikhat ha-Iggerot (pp. 458-460); and R. J. David Bleich, “Kohanim and Flights Leaving Israel,”TRADITION (Winter 2002). For more on the status of Pyrex and other recent material, see Piskei Teshuvot (vol. 5, p. 259).
As briefly referenced, much of the discussion regarding the status of aluminum and other newer metals has direct consequences for whether such utensils require ritual immersion. R. Feinstein issued several additional rulings on this topic that are worthy of mention such as his approach to disposable items (Y.D. vol. 3, #23) and his position exempting toasters from immersion (ibid., #24).
While R. Feinstein made brief mention of the concept of ohel zaruk, we should note that principle plays a more iconic role in the debate concerning umbrellas on Shabbat (see Responsa Noda be-Yehuda, O.H., #30 and Responsa Hatam Sofer, O.H., #72)
Finally, the entire discussion of kohanim flying, and our previous column on attending medical school, were all based on the premise that one can actually ascertain that any given person is indeed a kohen and subject to the associated restrictions. See Iggerot Moshe (Y.D., vol. 1, #230), where R. Feinstein himself addresses how kohanic lineage is identified nowadays.
Moshe Kurtz serves as the Assistant Rabbi of Agudath Sholom in Stamford, CT, is the author of Challenging Assumptions, and hosts the Shu”T First, Ask Questions Later.