The debate over contradictions, real or apparent, between Torah and science has been ongoing for centuries. The feud encompasses not only whether the two can be reconciled but how to do so. The conversation continues with a recent dispute between R. Natan Slifkin and R. J. David Bleich in the pages of Tradition and beyond. The latest round began with an article by R. Bleich, part of his regular column in the journal, on the subject of Anisakis parasites in fish (link, republished in Contemporary Halakhic Problems vol. VI). R. Slifkin wrote a strongly worded letter to the editor about the article (link), to which R. Bleich responded with a highly critical, full-length article (link), to which R. Slifkin further responded in a highly critical manner on his blog (combined in this file: link – PDF).
I wish to address here only a limited aspect of the exchange — the facts. It seems to me that there is a good deal of misunderstanding in the discussion. I will list, in note format which assumes you have read the material, what I believe are the key criticisms and evaluate their accuracy. I will ignore the literary aspects, including tone, style and structure, even though they are important and deserve attention. And while I acknowledge that R. Bleich is a much more credentialed, experienced and frankly impressive scholar, I will set that aside and deal here only with the arguments on their own merits, treating both individuals with equal respect. The term “factchecking” is probably a sensationalist overstatement of this post. The decisions required here are sometimes less than clear cut, for which I will use my judgment.
Some technical notes: I will refer to R. Bleich’s original article as B1, his second article as B2, R. Slifkin’s letter as S1 and his collected blog responses as S2. In parentheses, I will note the page numbers as printed on the page bottom of each file. My comments are enclosed in brackets. In expressing the authors’ points, I will sometimes adapt their own language and other times use my own words.
And now to the issues:
- S1(80). In his original article, R. Bleich fails to mention the approach that Sages were wrong on science.
B2(57). Mentioning that approach is unnecessary. None of R. Bleich’s solutions involve a claim of the Sages’ scientific inerrancy.[R. Slifkin is correct that R. Bleich omitted the view that the Sages were wrong on science in the case of parasites in fish (more on this below). However, once omitting that approach, R. Bleich had no need to discuss the general subject of whether the Sages’ science was correct because the approaches he cites entirely avoid the issue.]
- S1(80-81). What does the Gemara permit?
B2(56). The key question is what the Gemara forbade: parasites swallowed by a fish, which are not products of spontaneous generation.
B2(74). Repeats four suggestions from original article of what the Sages permitted.
S2(9). Absent viable alternative, the Sages were referring to Anisakis and similar parasites.[Both are correct. Clearly, R. Bleich believes he has presented at least one viable alternative. However, according to R. Slifkin’s approach, the key question is what the Gemara permitted. According to R. Bleich’s four approaches, that question is irrelevant.]
- S1(79). Resolution of whether Gemara bases decision on spontaneous generation is important.
B2(56). Anisakis issue is orthogonal to that of spontaneous generation.[Again, both are correct. According to the four approaches R. Bleich presents, spontaneous generation is indeed irrelevant to the Anisakis issue. According to R. Slifkin’s approach, it is key.]
- S1(79-80). R. Bleich argued based on an appeal to consequences. [R. Slifkin is incorrect. R. Bleich only stated – B1(89) – that that no posek has advocated such an approach in regard to parasites in fish.]
- B2(79-80). Halakhic decision-making does not involve selecting rejected, idiosyncratic views.
S2(8). R. Slifkin isn’t making halakhic decisions.[R. Slifkin is correct. While this is a halakhic matter, R. Bleich writes a survey column in which he regularly catalogs minority views.]
- S1(80). R. Bleich contrives within the Gemara a case in which worms in fish are generally not permitted.
S1(81). Microscopic approach is anachronistic and apologetic.
B2(60). There is nothing contrived or anachronistic about the case/approach.
S2(3). The overwhelming evidence is against the microscopic approach.[R. Bleich is correct. While I’m convinced that R. Slifkin’s approach is the most plausible, I don’t see overwhelming evidence and the determination of what is contrived and anachronistic is highly subjective.]
- S1(79). An honest reading shows that the Gemara’s ruling is based on spontaneous generation.
B2(57-62). R. Bleich presents four other readings and shows that they are honest.
S2(1-5). All other readings are scientifically indefensible.[R. Bleich is correct. He is only trying to show that the four approaches maintain internal coherence, i.e. honesty, which is the issue R. Slifkin raised in his letter. R. Bleich is not arguing their plausibility and even explicitly questions the plausibility of some. I believe the microscopic approach is scientifically defensible.]
- S2(3). The microscopic approach contradicts the commentaries of the Rishonim. [R. Slifkin is incorrect. The microscopic approach explains, rather than contradicts, the terminology of the Talmud and Rishonim. R. Slifkin finds that explanation unconvincing (as do I).]
- S1(79). R. Bleich omits the approaches of R. Glasner and R. Herzog.
S1(80). R. Lampronti and R. Kafach adopted a similar approach regarding lice on Shabbos.
B2(58). But they did not say so regarding parasites in fish and that is all R. Bleich originally claimed – B1(89). Additionally, R. Lampronti only relied on this approach to lice le-chumra.
B2(63). The sources R. Slifkin quotes from R. Kafach and R. Herzog do not assert that the Sages relied on incorrect science but can be read to mean nishtaneh ha-teva.
S2(6). Elsewhere R. Kafach states that the Sages based halakhah on incorrect science and elsewhere R. Herzog says Sages were incorrect on science.[R. Bleich is correct that he originally only referred to sources that directly discussed parasites in fish and made no claims beyond it. He even quoted R. Lampronti in footnote 69 to his original article. In his second article, he explicitly addressed only the sources R. Slifkin quoted in his letter. “Elsewhere” is relevant for the topic but not a valid criticism of R. Bleich.
In my opinion, the other citation from R. Kafach is convincing but the citations from R. Herzog are not self-evidently examples of the Sages basing halakhah on incorrect science.
R. Slifkin is correct that R. Bleich continues to omit R. Glasner’s view of the Sages’ scientific errancy.]
- S1(80). R. Glasner and R. Herzog say that we follow the Gemara’s rulings even when they are based on wrong science, similar to R. Fisher’s approach.
B2(69). R. Fisher’s approach does not apply to rulings based on empirical error. R. Glasner would follow empirically incorrect Talmudic rulings but not for the reason R. Slifkin asserts.[R. Slifkin is correct about R. Glasner and R. Bleich concedes that point.
R. Bleich appears correct about R. Fisher but I have to reserve judgment until re-reading R. Fisher’s essay more carefully.]
- B2(63). Those Rishonim and Acharonim who said that the Sages utilized incorrect science only said so outside the context of halakhah.
S2(5). There is no reason to distinguish between halakhah and other areas.[A case for distinction can be easily made.]
S2(5). The Sages demonstrably relied on gentile scientists for halakhah.[Perhaps only when the scientists of that time were correct.]
S2(5). R. Eliezer of Metz says halakhah was based on theory sun travels under the earth at night.[Refutation requires finding a Rishon or Acharon who explicitly says the Sages based a halakhah on science that the Rishon or Acharon deems incorrect. I believe examples can be found but I haven’t done the homework and careful re-reading required.] [It is not clear to me whether R. Bleich or R. Slifkin is correct about this. I suspect R. Slifkin is correct but he failed to prove it.]
- S2(11-Appendix I). R. Bleich’s ruling on brain death stems from his “non-rationalist” approach to the Sages and science. [R. Slifkin is incorrect in calling R. Bleich’s approach “non-rationalist” unless he uses this term idiosyncratically. Additionally, this charge is true of nearly every halakhic ruling on brain death, including those of R. Moshe Feinstein, R. Moshe Tendler and Dr. Avraham Steinberg (although not that of R. Nachum Rabinovich).]
- S2(12-Appendix II). R. Slifkin quotes a reader who asked R. Hershel Schachter about this issue and R. Schachter explicitly adopt R. Glasner’s approach, that the Sages were mistaken but we must nevertheless follow the Talmudic ruling. [This is incorrect. There must have been a miscommunication because R. Schachter recently published an article on the Anisakis issue in the OU journal Mesorah (no. 25). On page 74, R. Schachter quotes R. Glasner and rejects his approach, or at least terms it “difficult to accept,” and then suggests two other approaches. I obtained permission from the OU to post R. Schachter’s article here: link.]
Harsh words often confuse issues and the current debate offers such an example. I attempted here to avoid the sharpness and focus solely on issues. The discussion is certainly not over but can only move forward productively if we continue to speak politely, clearly and on topic.
Please note that comments on literary issues — tone, style and structure — will be deleted due to my desire to avoid discussing those issues here.