The Role of Archaeology in Halachic Decision Making – Part Two by Rabbi Chaim Jachter



In our previous issue, we outlined the debate among various authorities about whether archaeological finds constitute a legitimate tool to help resolve Halachic issues.  We saw that this debate began in the time of the Rishonim and appears to emerge as a dispute between the Chazon Ish and Rav Kook during the first half of the twentieth century.  In this essay, we shall explore how this dispute still rages today and how it applies to disputes regarding the identification of Techeilet, construction of Mikvaot, and the placement of Mezuzot.  If you missed last week’s article, it is available on our website,

The Techeilet Controversy

In the early 1990’s, Rav Eliyahu Tevger (a leading Rav at Yeshivat Merkaz HaRav) and others (see Techumin 9:425-428) sought to demonstrate that the murex trunculus (a type of snail) is the Chilazon that is the source for producing Techeilet used to dye Tzitzit.  Among his proofs are archaeological finds including the discovery of huge mounds of shells of the murex trunculus on the Northern Israeli coast alongside dyeing vats.  This claim sparked a great controversy, as some believed that it was likely that a Mitzvah that had been lost from Am Yisrael for more than one thousand years had finally been restored, while others were skeptical about this claim.  This remains a matter of controversy as some Jews wear Tzitzit with a blue string dyed with the dye of the murex trunculus and others do not.

Rav Yosef Shalom Eliashiv (a leading Israeli Posek) argues against wearing this Techeilet (Kovetz Teshuvot 2).  One of his arguments is that the Radzhiner Rebbe claimed in the late nineteenth century that he had rediscovered the lost Techeilet.  Subsequently, in the early twentieth century, Rav Yitzchak Herzog demonstrated that the Radzhiner’s identification of the Techeilet was incorrect and argued that the Techeilet is from a snail known as the Janthina.  Rav Eliashiv writes that now in the late twentieth century, Rav Herzog’s claim has been refuted and a different snail is reputed to be the authentic source of Techeilet.  Rav Eliashiv argues, “And we do not know if, in the coming years, others will come and disprove their claim as well.”

Indeed, Rav Eliashiv’s skepticism has ample precedent among the Acharonim.  Rav Yonatan Eibeshetz (Kreiti Upleiti 40:4) writes that scientific claims should be treated with great skepticism.  He notes that although the works of Galen and Aristotle were accepted as truth for many centuries, today they are dismissed as incorrect.  Rav Kook (Teshuvot Daat Kohen 140) also writes that Halacha treats scientific claims as only possibly correct.  Indeed, Rav Kook argues that the reason we rely on a physician’s assessment that someone must eat on Yom Kippur is that we merely consider the possibility that he is correct (Safek Nefashot Lihakel). 

Rav Hershel Schachter and other leading Poskim, on the other hand, consider the current identification of Techeilet as being possibly correct (Safek Techeilet).  Furthemore, Rav Tevger’s identification is based on the work of Rav Herzog, which is based on the work of the Radzhiner Rebbe.  Each generation advances the process of identifying the Techeilet and does not simply dismiss the work of the previous generation.  Indeed, the contemporary Poskim who advocate wearing the Techeilet believe that at some point the archaeological and other evidence is sufficiently convincing to at least rise to the level of Safek.  Moreover, there are times that Poskim accept certain scientific claims as certainly correct, as seen in the extensive Halachic literature on this topic, especially in the context of Hilchot Niddah (see the entry in Dr. Avraham Steinberg’s Encyclopedia of Halacha and Medicine, “Ne’emanut HaRofeh”). 

The advocates of the “new” Techeilet believe that while it is wise to maintain a healthy skepticism about archaeological and other scientific claims, it is also wise to keep an open mind about these claims.  Thus, it appears that Poskim in collaboration with archaeologists should evaluate each find to determine whether it should be considered in the process of rendering Halachic decisions (as we shall discuss more fully in next week’s essay). 

Can Archaeological Discoveries Substitute for a Mesorah?

Among the reasons presented against acceptance of the “new” Techeilet is the argument that a tradition from our ancestors is necessary to identify the authentic Chilazon.  Indeed, Rav Yosef Dov Soloveitchik (Shiurim Lizecher Abba Mari Z”l 1:228) cites that his great grandfather, Rav Yosef Dov Soloveitchik (author of the Beit HaLevi) rejected the Radzhiner Rebbe’s identification of the Techeilet precisely for this reason.  The Rav argues that just as we know that the Etrog is the Pri Etz Hadar mentioned in the Chumash purely as a result of a tradition that is handed down from generation to generation, so too, the identity of any species of animal or plant involved in the fulfillment of Mitzvot must be passed down from generation to generation.  This approach by definition rejects the possibility of reviving a lost tradition before the arrival of the Mashiach.  The Aruch Hashulchan (Orach Chaim 9:12) seems to adopt Rav Soloveitchik’s approach as well, as he writes that the Mitzvah of Techeilet will not be restored until the time of Mashiach. 

I heard that an interesting response to this assertion is offered by Rav Shabtai Rappaport (Rosh Yeshiva of the Yeshivat Hesder in Efrat).  He reportedly argues that Mashiach himself will be identified by Simanim, namely, that he will match the description of Mashiach that is outlined in the Tanach, Rambam and other sources.  Thus, he argues that we can identify the Techeilet in a similar manner that we will eventually identify the Mashiach, since the Gemara in various places describes various aspects of the process of making Techeilet.  On the other hand, one could argue that this is precisely why it is necessary for Eliyahu HaNavi to precede the arrival of Mashiach to identify the authentic Mashiach. 

Rav Hershel Schachter (Nefesh HaRav p. 53 footnote 26) notes that the Radzhiner Rebbe published a letter from the author of the Beit HaLevi that differs significantly from the approach that is presented by his great grandson.  In this letter (printed in Ein HaTecheilet page 13 and reprinted in Rav Menachem Burstein’s HaTecheilet) the Beit HaLevi calls attention to the issue that the tint fish (and the method of extracting its dye) that was identified by the Radzhiner Rebbe as the Chilazon was known among Torah scholars for many generations and they never identified it as the Chilazon.  Thus, we have a “de facto Mesorah” about this fish that teaches that it is not the authentic Chilazon.  By contrast, Torah scholars in earlier generations seem not to have known about the murex trunculus as it is a rare snail.  Moreover, the method of obtaining a sky blue dye from this snail was unknown for many years until it was discovered serendipitously in a laboratory in Israel during the 1980’s. 

The letter published in the Radzhiner’s work does not disprove the Rav’s presentation of his ancestor’s idea to be incorrect.  It simply shows that the Beit HaLevi articulated different approaches to our issue.  However, the idea articulated in the letter does present an alternative approach to that presented by the Rav, and leaves open the possibility of restoring a lost tradition through the use of archaeology.  In fact, the Beit HaLevi wrote in his letter “that if this tint fish (or the method of procuring its dye) was lost and newly rediscovered we would be obligated to listen to [the Radzhiner] and wear [his Techeilet].” 

Rav Eliashiv, though, raises another problem with reviving the Mitzvah of Techeilet today.  He notes the lack of a Mesorah regarding how to resolve disputes among the Rishonim regarding the production of the Techeilet.  Rav Elazar Meyer Teitz similarly noted (in a personal communication) the lack of a Mesorah of how to resolve the disputes among the Rishonim regarding how to tie the knots of the Tziztit and how many strings of the Tzitzit to dye with the Techeilet.  Other Rabbanim, such as Rav Hershel Schachter, argue that sufficient analytical bases exist in the Shulchan Aruch and the Mishnah Berurah (for example, Mishnah Berurah 9:7) to resolve these disputes.  One could also cite the precedent of Shmittah and other Eretz Yisrael-dependent Mitzvot, regarding which modern age Poskim have resolved Halachic issues despite the absence of clear Halachic precedent. 

Another core issue regarding the Techeilet is whether there is any Halachic risk involved in wearing the “new” Techeilet.  Rav Eliashiv argues that there is a Halachic risk involved if the Techeilet in one’s Tziztit are not authentic, as the Shulchan Aruch (Orach Chaim 9:6 and see the Pri Megadim cited in the Mishnah Berurah 9:15) cites an opinion in the Rishonim that the color of the Tallit should match the color of the strings (the Tzitzit) that we attach to the Tallit.  One could respond, though, that the Shulchan Aruch does not rule, essentially, in accordance with this opinion.  Indeed, Rav Yechiel Michal Tukachinsky (Ir HaKodesh Vihamikdash 5:55) writes, regarding the Radzhiner Techeilet, that there is no Halachic downside to wearing this Techeilet (“if it does not help, it does not harm”).  Furthermore, Rav Chaim David Halevi (Asei Lecha Rav 8:1) writes that since there is no Halachic downside to wearing the wrong Techeilet, one is obligated to wear what is thought might be Techeilet since there is a chance that it might be the authentic Techeilet.  It also should be noted that Rav Kook was receptive to the Radzhiner Techeilet (see Rav Burstein’s HaTecheilet p. 192).  Of course, since we are not certain that we have succeeded in identifying the correct Techeilet, one should not attach wool Tzitzit even with the “new” Techeilet to a four cornered linen garment (see Shulchan Aruch O.C. 9:2).  


By contrast, the fact that archaeological evidence indicates that our ancestors affixed their Mezuzot in the vertical direction (see Sinai 98:23-38) in harmony with the view of Rashi and the Sephardic tradition, should not move Ashkenazic Jews to change their custom of placing their Mezuzot on a slant on the door.  The Ashkenazic tradition seeks to compromise between the view of Rashi who holds that the Mezuzah should be placed vertically on the door and Rabbeinu Tam’s view that it should be placed horizontally (see Rama Shulchan Aruch Yoreh Deah 289:6). 

Parenthetically, we should explain that Mezuzot used to be placed in holes etched into the doorways (as one can see in some old homes in the Old City of Jerusalem).  This is how one can draw evidence about the way Mezuzot were affixed to homes in antiquity through archaeological evidence.   

There are two reasons not to change our tradition.  First, the archaeological evidence is inadequate.  We noted last week that only a small percentage of the items have survived through the ages.  Moreover, only a tiny percentage of remains from the ancient world have been excavated.  Thus, one cannot draw conclusions from what we have not found.  It is entirely possible that homes where the Mezuzot were affixed in accordance with Rabbeinu Tam will be found, just as Tefillin have been found that match both Rashi and Rabbeinu Tam’s opinions about the order of the Parshiot. 

The second reason is that we should not abandon our tradition even in light of archaeological evidence.  We have seen with respect to the Techeilet that archaeology can possibly play a role when there is no Mesorah (tradition).  It certainly cannot uproot a tradition.


There is no exclusive tradition on how to construct a Mikveh.  In fact, we outlined in articles we wrote on the subject a few years ago (available at that there are at least five styles of Mikveh construction that are employed throughout the world today.  Accordingly, the question arises whether all Mikvaot should now be adapted to the approach of the Chazon Ish and Hungarian Jewry whereby Mikvaot are constructed to function using only the Zeriah method of rendering the water in the immersion pool as Kosher, as it seems was done in the Mikveh on Massada (see Techumin 17:389-398).  Can we conclude from the Mikveh on Massada that this is the way that our ancestors arranged their Mikvaot and therefore we should follow in their path regarding this specific issue? 

The answer is a resounding no.  Since we have uncovered only a few of the ancient Mikvaot, it is inappropriate to draw conclusions from these artifacts.  Moreover, perhaps the Mikveh at Massada was constructed at the highest standard that was possible to be practiced in the ancient Judean desert at that time.  Indeed, Rav Moshe Feinstein (Teshuvot Igrot Moshe Yoreh De’ah 1:111) rules that while it is preferable for a Mikveh to employ both the methods of Hashakah and Zeriah, nevertheless, if it is only possible to make the Mikvaot using either only Zeriah or only Hashakah, the Mikveh is undoubtedly acceptable.  Accordingly, we should not be disturbed by the fact that the Mikveh in Teaneck, for example, is constructed at a higher standard than the Mikveh in Massada.  Obviously, we have much easier access to water in Teaneck than did our predecessors in Massada and have the practical capabilities of achieving higher Mikveh standards that were beyond the reach of the residents of Massada.   


The dispute between the Chazon Ish and Rav Kook in the early part of the twentieth century has continued to rage among the Poskim of the latter part of the twentieth century.  However, all agree that archaeology cannot uproot an accepted tradition among the Poskim.  Next week, we shall conclude our discussion of the interface of Halacha and archaeology and discuss the question of the impact of archaeology on the proper date for reading the Megillah and identifying bones.

The Role of Archaeology in Halachic Decision Making – Part Three by Rabbi Chaim Jachter

The Role of Archaeology in Halachic Decision Making – Part One by Rabbi Chaim Jachter