Why R’ Herzog Hesitated
The Murex was not the only creature proposed as the Chilazon, and that is where this particular debate starts getting interesting. Long before the modern Murex revival, Rav Yitzchak Herzog had already spent years investigating Techeiles from almost every angle available to him. He worked through the Torah sources, corresponded with scientists and scholars, studied the ancient Mediterranean dye industry, and tried to make all of that line up with the descriptions of the Chilazon found in Chazal.
The historical and archaeological evidence already pointed strongly toward the Murex family as the great shellfish-dye source of antiquity. Huge quantities of Murex shells had been found at ancient dyeing sites, and classical writers described an industry that fit the same general picture. Herzog nevertheless had trouble fitting the Murex neatly into several of the traditional simanim of the Chilazon. In his day there was also still uncertainty over how the expected blue could actually be produced from it.
Janthina Enters the Picture
Those difficulties pushed Herzog toward another Mediterranean sea snail, Janthina. Janthina had almost the opposite attraction. It floats near the surface of the sea, has a striking bluish-violet appearance, and at first glance seems to fit descriptions such as gufo domeh layam — “its body resembles the sea” — more naturally than the rather ordinary-looking Murex sitting on the sea floor.
If one begins with the simanim and asks which creature sounds most like the animal Chazal are describing, Janthina can look surprisingly good. The problem begins once the question changes from what the Chilazon should look like to what animal was actually being harvested and used for expensive textile dye in the ancient Mediterranean. There the evidence swings heavily toward the Murex.
Murex Has a Different Kind of Evidence
Janthina therefore has almost the reverse strengths and weaknesses of the Murex. The Murex has an enormous archaeological footprint. Ancient dye sites contain piles of broken shells, Greek and Roman writers describe a major shellfish-dye industry, and the animal contains the chemical precursors needed to produce blue and purple dyes. Those colors can actually be reproduced from the snail today.
Janthina may seem to fit some of the simanim more literally, especially if those descriptions are read as zoological markers. What it does not have is anything comparable showing that the ancient Mediterranean world harvested Janthina on a large scale for textile dyeing. That gap would become one of the main problems hanging over the Janthina identification.
Kaplan Revives Janthina
Much later, Dr. Shaul Kaplan returned to Herzog’s Janthina idea and developed it much more aggressively. Kaplan argued that Janthina deserved to be taken seriously precisely because the simanim seemed to fit it so well. From his perspective, the descriptions in Chazal could not simply be treated as vague remarks that had to be reinterpreted after archaeology had already identified the animal.
In other words, Kaplan was starting from the opposite end of the problem. Rather than asking which ancient shellfish is known to have produced luxury dye and then working backward through the simanim, he wanted the simanim themselves to carry substantial weight in deciding which creature ought to be identified as the Chilazon.
Schlesinger Defends Radzyn
The discussion in Beis Aharon V’Yisrael, however, did not begin as a straightforward Murex-versus-Janthina debate. R’ Meir Schlesinger entered the subject from the direction of the Radzyner Rebbe and his cuttlefish identification, defending both the older Radzyner position and the reasoning behind it.
That matters because there were now three very different approaches sitting on the table. Radzyn had a nineteenth-century Torah argument which had developed into a living Chassidic mesorah. Janthina appeared to fit a number of the traditional simanim remarkably well. The Murex, meanwhile, had something the other two did not have in remotely the same degree: the physical remains of the ancient Mediterranean dye industry.
Shapira Brings Janthina Into the Debate
R’ David Shapira responded to Schlesinger, and in the course of that discussion he brought Kaplan’s Janthina arguments into Beis Aharon V’Yisrael. At that point the debate broadened considerably. It was no longer simply a defense or rejection of the Radzyner Rebbe’s identification.
The question had become which of several candidates best accounted for the evidence as a whole. Depending on where one started, a different creature could look strongest. The Radzyner cuttlefish had one set of arguments behind it, Janthina another, and the Murex yet another.
Goldstein Makes the Case for Murex
R’ Yaakov Goldstein then entered the discussion and turned the focus much more directly toward the Murex. Rather than beginning with the question of which creature looked most like an individual description in Chazal, Goldstein emphasized the larger body of evidence pointing toward one particular shellfish.
The Murex was not merely an animal for which clever explanations could be offered after the fact. It was demonstrably used for dyeing in antiquity, its shells were found in industrial quantities at ancient dye-production sites, and its secretion could actually yield the relevant colors. The argument was cumulative: archaeology, history, chemistry and the physical remains of the dye industry were all pointing toward the same animal.
Kaplan and Shapira Answer Back
Kaplan and Shapira answered Goldstein and pushed back against several parts of his presentation. They defended the importance of the simanim and argued that the traditional descriptions could not simply be pushed aside because archaeology seemed to favor the Murex. They also challenged particular factual claims and the way some of their arguments had been presented.
That is part of what makes this series especially useful. It was not one writer publishing a theory and everybody else moving on. The arguments were challenged, clarified and then argued over again in later issues.
Goldstein Returns
Goldstein eventually returned to the subject with another response. By that point the discussion had moved beyond the simple question of whether Janthina or the Murex was the better-looking candidate. The deeper disagreement was over how the various categories of evidence were supposed to interact.
There was also an important distinction between identifying the animal and proving every detail of the modern dyeing process. Those two questions were sometimes treated as though they were identical, but they did not necessarily have to rise or fall together. A person could consider the Murex identification convincing while still asking whether every technical detail of producing Techeiles from it had been reconstructed correctly.
What Are the Simanim Supposed to Prove?
Underneath the zoology was a much larger methodological question: what exactly are the simanim in Chazal supposed to do? If they were intended as a practical identification checklist, then a creature that appears to match them more literally has a very serious claim even if its archaeological record is weak.
But it is also possible that not every description was intended as the equivalent of a modern field guide. If archaeology, chemistry, classical sources and the ancient dye industry all converge upon one creature, an apparently difficult siman may need to be understood differently rather than used immediately to reject the identification.
The difficulty works in both directions. If an archaeologically attractive candidate requires strained explanations of every description in Chazal, critics can reasonably ask whether the evidence has really identified the Chilazon at all. On the other hand, a creature that matches several descriptions beautifully but leaves no trace of ever having been used for the dye under discussion has a rather serious problem of its own.
Which Evidence Gets Priority?
That is why the Janthina debate is more useful than it first appears. Janthina becomes very attractive when the discussion starts with appearance and a literal reading of individual simanim. The Murex becomes much harder to avoid when the ancient industry, shell heaps, chemistry and historical record are placed on the table together.
The Radzyner cuttlefish adds yet another element. Whatever one thinks of the identification itself, it came with the arguments of the Radzyner Rebbe and later acquired a continuous practice within Radzyn. So the three candidates were not merely three marine animals competing over which one looked most convincing. Each represented, to some extent, a different way of weighing evidence.
The writers were therefore arguing over more than an isolated fact or two. They were arguing about which kinds of evidence should control the identification in the first place, and what happens when those different forms of evidence do not seem to point in exactly the same direction.
Why the Debate Still Matters
The Beis Aharon V’Yisrael exchange gets to a question that comes up repeatedly in modern Techeiles research. When textual descriptions seem to point one way while archaeology and physical evidence point another, which side is supposed to bend? Should the scientific identification remain doubtful because some of the simanim are difficult, or should those simanim themselves be reexamined once the historical evidence becomes exceptionally strong?
That is the real issue behind this debate, and it is why Janthina and the Radzyner cuttlefish are still worth studying even if neither is presently the leading candidate. They force the Murex case to answer a harder question than simply, “Was this snail used for ancient dye?” The fuller question is whether the Murex can account for the entire body of evidence — the archaeology, chemistry and historical record, but also the descriptions handed down by Chazal.
A Later Postscript: What Happened to Janthina?
There is also an interesting later development. After years of working with Janthina, Kaplan eventually acknowledged that he had not succeeded in producing a durable textile dye from it, while the Murex could demonstrably produce one. That seriously weakened Janthina as a practical candidate for the ancient Techeiles dye source. For a later account of Kaplan’s position and the broader history of the search for the Chilazon, see חלזונו של משיח.
