Sunday, June 3, 2018

Denying Chazal's Belief in Spontaneous Generation

There are many statements in Chazal referring to the spontaneous generation of various creatures. While this belief might sound absurd to people today, it was in fact entirely reasonable and normative in the ancient world - none other than Rambam ridicules those who do not believe it.

In the charedi world, the standard approach is to claim that this phenomenon indeed used to exist, but "nature has changed" and it is no longer found. (This runs into various difficulties, discussed in my book Sacred Monsters, which I shall not go into here.) A different approach, however, is found with charedi anti-rationalist rabbonim who seek to present themselves as sophisticated thinkers that are well-versed in science, such as Rabbi J. David Bleich and Rabbi Moshe Meiselman. They are dogmatically opposed to saying that Chazal predicated halachos on a misunderstanding of the natural world, so no matter how much evidence there is for that, they have to find a way around it. However, they can't bring themselves to insist that spontaneous generation really does take place (though R. Bleich does insist that it can't be disproved!) So they claim instead that Chazal never actually believed in spontaneous generation.

Now, one obvious problem with this approach is that the entirety of traditional rabbinic thought - every single Rishon and Acharon - interpreted Chazal as believing in spontaneous generation. Is it not preposterous, even arrogant, to claim that you understand Chazal's words better than every single Rishon and Acharon who ever lived? And it also goes strongly against the charedi ethos of claiming great respect for the mesorah and for traditional rabbinic authorities. 

But in this post I would like to concentrate on a different problem with this approach: the way in which its advocates conveniently ignore sources in Chazal which expose the impossibility of their interpretations.

I. Lice

Let's begin with the most famous case of spontaneous generation, that of lice. The Gemara says as follows:
Rabbi Eliezer said: One who kills a louse on Shabbos is like one who kills a camel on Shabbos (and has violated Shabbos)… Rav Yosef said: The Rabbis disagree with Rabbi Eliezer in the case of lice, which do not reproduce (and are thus not considered to be proper life-forms)… (Talmud, Shabbos 107)
This seems like a straightforward statement that lice spontaneously generate, which is indeed how all the Rishonim and Acharonim understood it. But R. Bleich and R. Meiselman both insist that when Chazal said that lice do not reproduce, what they meant was that lice do not reproduce in a way that is visually detectable. Halachah does not take into account microscopic phenomena, and that's what Chazal meant. (They do not attempt to explain why Chazal presented this in such a misleading way as to lead all the Rishonim and Acharonim astray.)

Now, the immediate problem is that lice actually do reproduce in a way that is visually detectable. Lice eggs are not too small to be seen by the naked eye. R. Bleich therefore claims that the Gemara is actually talking about a different, unknown species of louse. He does not acknowledge the difficulty of positing that lice infestations back then were a different species, nor of claiming that the halachic mesorah at one point changed to be referring to a completely different species!

R. Meiselman, on the other hand, claims that "what is sub-visual is not the egg itself... but the relationship between egg and parent", which he explains to refer to the cycle of lice laying eggs which then hatch into other lice. But that is not sub-visual either! So R. Meiselman argues that "since this relationship was not historically perceived (the ancients did not realize that lice hatch from nits - N.S.), the halachah treats it as non-existent." Whoah! So if ancient people didn't notice/realize something that is perfectly visible, then halachically it doesn't exist?! That is a staggering claim, with extraordinary ramifications! (So the sun doesn't halachically go on the other side of the world at night? And a baby born after an 8-month gestation is not halachically alive?)

Anyway, another problem is that the immediately ensuing passage in the Gemara shows that Chazal were aware of the possibility that lice hatch from eggs, and negated it:
Abaye said: And do lice not reproduce? Surely it was said, “God sits and sustains from the horns of aurochsen to the eggs of lice” (which shows that lice come from eggs)?—That refers to a type [of organism] which is called "eggs of lice" (but not that lice actually hatch from these). (Talmud, Shabbos 107)
Surely if Chazal did not believe in spontaneous generation, and were merely intending to negate sub-visual phenomena, then they could have just said that, yes, God sustains the eggs of lice, but they are sub-visual! R. Bleich and R. Meiselman both attempt to answer this, but in brief words that seem designed more to obfuscate than elucidate - after trying for a while to wrap my head around the cryptic contrivances, I just gave up.

But, at a broader perspective, any attempt to explain what Chazal had in mind when they described lice as "not reproducing" must surely take into account their general view of how creatures come into existence. And that leads us to our next mysterious creature: the salamander.

II. The Salamander

Chazal say the following about the salamander:
The Rabbis taught: “The tzav, according to its kind” (Leviticus 11:29) — to include the arvad, and also the nefilim, and the salamandra. And when Rabbi Akiva would reach this verse, he would say, “ ‘How diverse are Your works, O God!’ (Psalms 104:24) ...You have creatures that grow in the fire, and You have creatures that grow in the air; those which grow in the fire would die instantly if exposed to air....” (Talmud, Chullin 127a)
It was universally believed in the ancient world that salamanders are generated in fire, grow in it, and cannot survive outside it. If Chazal believed in the spontaneous generation of even a larger creature such as the salamander, why would they not have believed in the spontaneous generation of much lesser creatures such as lice? Also, here we have another case of Chazal having an incorrect belief about the natural world!

R. Meiselman, despite publishing an 800-page allegedly authoritative book on Torah and science, designed to refute the heresies presented by yours truly, simply doesn't mention salamanders. It's a source in Chazal that refutes his forced explanations, so he simply ignores it!

R. Bleich has the following to say about the salamander: "Aggadic references to mice arising from dirt (Sanhedrin 91a) and salamanders from fire (Hagigah 27a) have no bearing on this discussion. Quite frequently, aggadic statements involving exaggeration and hyperbole are allegorical and intentionally inaccurate. Illustrations of edifying teachings are often presented in terms best understood by the intended audiences."

What on earth is this supposed to mean with regard to the Gemara's statement about salamanders? It's not an exaggeration or hyperbole - it is a calm description of how this salamander lives and dies. There's nothing which indicates it to be allegorical or intentionally inaccurate. And it was certainly understood as a factual, accurate account by all the Rishonim and Acharonim. Moreover, R. Bleich fails to cite the following source from the Midrash Tanchuma:
There are creatures that thrive in fire, and not in air, such as the salamander. How so? When glassmakers heat the furnace for seven consecutive days and nights, out of the thick of the flames emerges a creature that resembles a mouse, which people call a salamander. If a person smears his hand with its blood, or any other of his limbs, fire has no power over that part of him, because a salamander is generated from fire. (Midrash Tanchuma, Vayeshev 3)
This is clearly a non-allegorical, non-hyperbolic description that is intended to be accurate. R. Bleich ignores this, presumably because it refutes his claims about Chazal's infallibility and about their not believing in spontaneous generation.

III. The Mud-Mouse

Finally, we come to the mouse that is generated from earth: 
A certain sectarian said to Rabbi Ami: You say that the dead will live again—but they become dust, and can dust come alive? He replied... Go out to the field and see the rodent that one day is half flesh and half earth, and on the next day it has transformed into a creeping creature and has become entirely flesh. (Talmud, Sanhedrin 91a)
Again, there is no reason whatsoever to accept R. Bleich's claim that this is hyperbole, allegorical, or intentionally inaccurate. Meanwhile, R. Meiselman claims that Rabbi Ami did not himself believe that such a creature exists, but was merely telling the sectarian that since he believes in it, he should not deny techiyas hameiseim. Of course, this is a remarkably strained interpretation.

Furthermore, refuting R. Bleich's description of the mouse as "aggadic," and challenging R. Meiselman's claim that Chazal didn't actually believe in its existence, is the fact that the Mishnah itself discusses the laws of such a creature:
A mouse which is half flesh and half earth; if someone touches the flesh part, he becomes impure; if he touches the earth part, he remains pure. (Mishnah, Chullin 9:6)
R. Bleich simply fails to mention the Mishnah. R. Meiselman claims that weren't definitively stating that they believe such a creature to exist, but they were "merely familiar with the persistent rumors of the creature's existence and wished to clarify its halachic status." But if they were open to the possibility that a mouse can be generated from earth, then isn't it overwhelmingly likely that they also believed that lice can be generated from sweat?

Furthermore, both R. Bleich and R. Meiselman fail to mention the following passage from Chazal about the mud-mouse, in which they actually expound a drasha from a passuk as specifically existing in order to address the mud-mouse!
I might think that a swarming creature causes impurity, but a mouse that is half flesh and half earth, which does not cause swarms, does not cause impurity. But it is logical: The rat causes impurity and the mouse causes impurity; just as “rat” is as its meaning, so too “mouse” is as its meaning (and thus a mouse that is half flesh and half earth would transmit impurity). Yet alternatively, one could say, just as the rat procreates, so too the mouse referred to is one that procreates, which excludes a mouse that is half flesh and half earth and does not procreate! Therefore it teaches us, “[And this is impure for you] among the swarming creatures [which swarms on the land]”—to include the mouse that is half flesh and half earth, that one who touches the flesh becomes impure and if he touches the earth he remains pure. (Midrash Sifra, parashas Shemini 5:6; Talmud, Chullin 127)
Are R. Bleich and R. Meiselman going to claim that Chazal had a drashah for a creature that they didn't believe existed?! Evidently it's much easier for them to simply ignore this Chazal.

The sad thing is that due to the impressive accomplishments of both R. Bleich and R. Meiselman in various fields, many people can't bring themselves to recognize their sophistry, irrationality and intellectual dishonesty in areas which challenge their anti-rationalist dogmas. That's the common mistake of those who do not follow Rambam's maxim to accept truth from wherever it comes - which has the corollary of rejecting falsehood from wherever it comes.


  1. R. Bleich and R. Meiselman both attempt to answer this, but in brief words that seem designed more to obfuscate than elucidate - after trying for a while to wrap my head around the cryptic contrivances, I just gave up.

    Quote those words here, perhaps? Maybe we can take a stab at them.

  2. As Tolstoy said “And not only the pride of intellect, but the stupidity of intellect. And, above all, the dishonesty, yes, the dishonesty of intellect. Yes, indeed, the dishonesty and trickery of intellect.”

  3. "though R. Bleich does insist that it can't be disproved!"

    Sigh. This is pseudo-scientific nihilism that could be applied to pretty much any scientific evidence. :(

  4. Just some interesting quotes by a couple of famous scientists about spontaneous generation:
    "The origin of the first Monera by spontaneous generation appears to us as a simple and necessary event in the process of the development of the earth. We admit that this process, as long as it is not directly observed or repeated by experiment, remains a pure hypothesis. But I must again say that this hypothesis is indispensable for the consistent completion of the non-miraculous history of creation, that it has absolutely nothing forced or miraculous about it, and that certainly it can never be positively refuted. It must also be taken into consideration that the process of spontaneous generation, even if it still took place daily and hourly, would in any case be exceedingly difficult to observe and establish with absolute certainty as such. This is also the opinion of Naegeli, the ingenious investigator, and he, in his admirable chapter on Spontaneous Generation, maintains that "to deny spontaneous generation is to proclaim miracles." ~ Ernst Haeckel (Professor of Comparative Anatomy)
    "The reasonable view was to believe in spontaneous generation; the only alternative, to believe in a single, primary act of supernatural creation. There is no third position. For this reason many scientists a century ago chose to regard the belief in spontaneous generation as a "philosophical necessity." It is a symptom of the philosophical poverty of our time that this necessity is no longer appreciated. Most modern biologists, having reviewed with satisfaction the downfall of the spontaneous generation hypothesis, yet unwilling to accept the alternative belief in special creation, are left with nothing." ~ George Wald (Professor of Biology at Harvard University Nobel Laureate)
    "One has only to contemplate the magnitude of this task to concede that the spontaneous generation of a living organism is impossible. Yet here we are as a result, I believe, of spontaneous generation." ~ George Wald

  5. Thanks for the interesting post.

    I wonder if the salamander is an astral creature, not a physical one. Or maybe chazal were simply taking the 'knowledge' of their time at face value. see

    After all most people believe without question the myths of our present culture, like people landing on the moon, or the twin towers falling down from an aircraft flying into them, or ISIS carrying out terrorist attacks in Europe.

    I don't think halocho takes things at other than face value.

    1. Chazal working within accepted "knowledge" of the era is exactly R' Slifkin's opinion (correct me if I'm wrong, please!)

      I assume your use of the word "myth" in the context of the present culture is used in jest. There are other scientific issues that have had varying understandings over the years you could have used as examples rather than resorting to conspiracy theories, as it undermines your point about Chazal.

  6. Not sure what Rabbi Slifkin thinks he is accomplishing with this sudden rehashing of old material.
    Very convenient for him to have neglected to mention that most of the points in this post were addressed and rebutted here:

    1. That's an amazing post. So Rabbi Meiselman claims that any animal that reproduces out of sight is aino para v'rava, and can be killed on Shabbos? All animals that give birth in burrows and dens and underwater?

      Also, I didn't see that you addressed the sources that R. Slifkin brought in this post - the ones that he said R. Meiselman keeps avoiding. So I guess you are a true talmid of R. Meiselman!

    2. Just checked things out over there. So your position is that the reference to the salamander is not to what we call a salamander, but to some other non-natural creature? I hope you realize how absurd this sounds. According to you, there is a creature that we know to be the salamander, which the ancients believed to generate from fire, but which we now know does not generate from fire, and that Chazal would have known that this creature did not generate from fire. In addition, there is another creature entirely, which Chazal also call a salamander, which was created from fire, but was non-natural. If this is your position, I understand why you shut down your blog.

  7. "R. Bleich and R. Meiselman both insist that when Chazal said that lice do not reproduce, what they meant was that lice do not reproduce in a way that is visually detectable. Halachah does not take into account microscopic phenomena, and that's what Chazal meant."

    I think this is a very tenable position. If we ignore those particular authors' context.

    Halakhah indeed does not take the microscopic into account, so when they speak of the realia behind a din, that is indeed what they meant. They may have meant it because they thought nothing microscopic was indeed happening -- but that's irrelevant to us.

    The dragon or dirt-mouse stories could very well have been "if so many people can believe X, why can't you believe Y?" whether or not either of the parties involve X. Again, your investing this much effort discussion whether or not R Ami actually believed such rodents existed is inconsistent with your own belief that R Ami's statements aren't valued for their ability to teach us about such things.

    By your own position, harping on about what Chazal didn't know scientifically is focusing on irrelevancies.

  8. One or two line statements { The Rabbis disagree with Rabbi Eliezer in the case of lice, which do not reproduce } are always open to many interpretations ,, like Pirkei Avos

  9. Rabbi Abraham ben HaRambam rejected the Talmud’s medical advice, so why can’t we simply reject spontaneous generation?

    Rambam Rejected Childless Messiah:

    1. because here there are Halachic ramifications

  10. Dear Zoo Rabbi, do we have any idea what Chazal were thinking when they claimed that salamanders came from fire? I mean, the ones I used to catch in summer camp in the Poconos came from the lakes and streams. What could they have been referring to?

  11. if "Halacha does not take into account micorscopic phenonema" (according to these illustrious Rabbis) then why does the chareidi world get into a frenzy about checking fruits and salads with microscopes, totally ignoring the plain fact that nothing can be seen with the naked eye?

    1. Who is this Charedi world? Do all Charedim have microscopes at home? Because nobody that I kbow owns one.

    2. there are no microscopes. as far as light boxes and loops, they help *recognize that which the naked eye can *see.

  12. "...the mouse that is half flesh and half earth, that one who touches the flesh becomes impure and if he touches the earth he remains pure"...

    Is the peshat of this not simply talking about contracting or remaining pure, based on whether you touch the decayed part or the intact part of a rotting mouse? Where is there any room for interpretation that this is talking about a *species* of mouse rather than the *state* of the mouse?

    Shouldn't this be obvious?

  13. Regarding the "microscopic" interpretation of the lice Gemara, I've always wondered: is the procreation of lice truly harder to observe than the procreation of every single species that one may not kill on Shabbos? Aren't there lots of small insects? Are lice particularly small?

    1. R. Slifkin, I'd be curious for your input on this because of your vast zoological knowledge. Are lice particularly hard to see, compared to other non-microscopic insects? Would there be a legitimate reason for Chazal to have singled out lice on account of their size or visibility, even if they were not believed to be spontaneously generated?

  14. And your last sentence sums up the whole discussion brilliantly!

  15. Rs Bleich and Meiselman also have to deal with the Chazon Ish, who in Emunah veBitachon expressly refers to to bolster emunah:
    "The force of habit dulls the sense of the excitement that one should have upon seeing any form of life, but one feels excited when presented with rare, unusual species such as an elephant, a monkey, a mouse that is half earth and the adnei hasadeh". The Chazon Ish (Rabbi Avraham Yeshayahu Karelitz 1878-1953) clearly regarded Sanhedrin 91a and Chulin 127a as proof of the existence of mud mice.

  16. For the umpteenth time, there is a difference between physical and legal reality. At 17 years and 364 days old you are not allowed to purchase real estate or firearms, vote, serve on a jury or in the military, etc. The next day you can do all of these things. You did not magically become emotionally mature enough to do these overnight, it is a legal line, and it need not correlate with anything physical. On the halakha end of this, there is minimal difference between today and tomorrow on a physical level, but if today is Friday, we are literally willing to kill you for doing the exact same things tomorrow as you are doing today. Similarly, if you declare your intention to donate a sheep to the beit hamikdash, your legal interactions with the sheep have changed drastically despite the sheep remaining both unchanged and oblivious to the whole proceeding. Given that we draw lines between physical and legal reality in Judaism such as between shabbat and chol, hullin and heqdesh, etc., what is so unsavory about saying that this established legal reality does not correspond to physical reality?

    1. It's completely unobjectionable, so long as you acknowledge you're doing it.

    2. All 'categories' (halachic or scientific) are created by humans and therefore only correspond more or less to reality as we perceive it.

      The problem is what do you do when chazal clearly based their Halachic categories on their pre-existing scientific categories and now we know that their scientific categories were wrong.

  17. Hello,

    You are a wealth of knowledge and information. The tanchuma you quoted about the "fire creature", which is used in many places, compared to the protection Torah avails your from the "fires of hell". You think they meant to be taken literal? You think that they intended to teach what they thought was a recipe for a firman suit mad of salamander blood? Seems to any honest reader as allegory. I think you have drifted from your normally straight and scholarly way with that quote, to attempt prove a mute point.

    May you continue to open up the arms of the Torah for all of our people.


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