Summary: Chazal and Mistakes in Science

Updated on 7/7

I.Introduction

There has been a dispute raging about whether Chazal could make mistakes in science or not. This is not a new question, it is a dispute in the Rishonim. What is new is the attempt by some to state that the opinion that Chazal could make mistakes in Torah is rejected and to hold that way today is kefira. R' Feldman champions this position in his letter:

R. Yosef Shalom Eliashiv, a signatory to the ban, was asked: if he considers Slifkin’s approach wrong how could so many earlier authorities have held it? He answered: “They were permitted to hold this opinion; we are not.”1 In other words, they were authorities in their own right qualified to decide matters of Jewish law. We are not permitted to do so.2 We are enjoined to follow the majority opinion and our tradition as to how we are to approach Torah.

Since we are not permitted to follow Slifkin’s views, R. Eliashiv believes that they can be rightfully categorized as heresy (apikorsus) as the ban’s wording had it. I believe this is because they diminish the honor and the acceptability of the words of the Sages, which has the status of apikorsus.

R' Feldman in his letter also tried to bring proofs as to why the opinion that Chazal did not make mistakes in science is correct.

I am not not on R' Feldman's level, but תורה היא וללמוד אני צריך, and therefore I am going to write my opinion. All I ask is that the reader consider both sides of the argument and make a decision on which argument is better. I believe that his proofs and answer are not proofs and in fact raise more questions then they answer.

I have posted detailed rebuttals to all of his proofs
Is נשתנה הטבע a viable answer for conflicts between Torah and science?
Is סוד ה' ליראיו a reason to believe that Chazal didn't err in science?
Is Kabbala proof that Chazal could not make mistakes in science?

In this post I am going to summarize the main arguments so that they are all in one place.

II. The claim: Chazal did not make mistakes in science

R' Feldman writes
Either they had a tradition directly teaching them these facts, or they knew them by applying principles which were part of the Oral Torah regarding the inner workings of the world.

In other words, all of Chazal's science is Torah M'Sinai.

III. The problem with the claim

R' Feldman himself points out the problem with the above claim.

There are many places in the Talmud where statements made by the Sages seem to contradict modern science. The most common are the cures and potions which the Talmud gives for various diseases. Our great halachic authorities have noted the phenomenon that these cures, in the vast majority of cases, do not seem to cure illnesses in our times.

One note, there are many many other issues besides the cures.

IV. The answer

R' Feldman offers the following answer
The most widespread explanation offered for this is nishtanu hatevaim, “nature has changed” - cures that worked in the times of the Talmud are no longer effective.1 There are many examples of illnesses and cures, which because of environmental and nutritional differences and physical changes to the body over the years are no longer effective.

In other words, everything Chazal said was true, but some time afterwords nature changed.

V. The problems with nishtanu hatevaim

In truth, nishtanu hatevaim, raises more questions then it answers. For a more detailed rebuttal see Is נשתנה הטבע a viable answer for conflicts between Torah and science?

Here is a summary of the problems:
1. They hold that all of Chazal's science is part of Torah. This means that when Chazal said that remedy x cures sickness y, that was part of Torah, it was received at Har Sinai. Why doesn't it work today? The world changed. This makes no sense. Torah preceded the world by 2000 years (Gemara Shabbos). Hashem created the world by looking into the Torah. How can you say that things in the Torah are no longer true? For over 4000 years remedy X cured Y, suddenly after the era of Torah Shebaal Peh ended the world changed so this stopped working and the torah became untrue, why would Hashem do such a thing? It makes Torah into a joke. Why would Hashem change the world so that Torah no longer reflects the world if the world was created based on Torah.

Even more then that, this seems to contradict the Rambam's principle of the immutability of Torah. Torah has now changed. It used to be that the Torah provided a rememdy for sickness Y, now it no longer does. It used to be that the Torah explained various natural phenomena, now it doesn't. In other words the Torah changed because it no longer reflects the physical world.

2. If Chazal had a kabbala (tradition) about science you would think that they would have had a kabbala that the world is going to change and that the science would no longer be true. נשתנה הטבע should also be part of Torah. After all, if you are going to claim that all of science is in Torah then this very important fact should be there as well. Yet, Chazal never even hint that the scientific pronouncements that they are making are only temporary. They didn't say that remedy X will only work for a limited time. they made a blanket statement that remedy X cures Y. It is clear that Chazal had no idea that נשתנה הטבע was going to happen, why not? If Torah included science it should have included נשתנה הטבע as well.

3. There is not a shred of evidence that נשתנה הטבע. Remember, the Geonim who lived only a few hundred years after the time of the gemara already stated that the cures of Chazal don't work, that is a very short time. Here are some examples of things where it is quite implausible to say that נשתנה הטבע.
a. The Gemara in Bava Basra (25a) states clearly that Chazal held that the Sun revolves around the Earth and that the Earth is surrounded by a roof that the sun goes out of at night (see Chazal and Mistakes in Science for more about this). It would be preposterous to claim that in the times of Chazal the Sun revolved around the Earth and went out a window but now נשתנה הטבע and the Earth revolves around the sun etc. Everyone can understand that such a change didn't happen.
b. The gemara seems to say that lice are born from spontaneous generation. again it is not plausible to think that in the times of Chazal there was spontaneous generation but in the last 1500 years it stopped
c. The gemara states that the mother contributes the blood to the baby (based on this some poskim didn't want to accept blood tests to establish paternity). It is implausible to think that the whole nature of human development changed after the time of chazal.
...

VI. His Proofs: G-d would not have permitted falsities to have been transmitted as Torah She-be-al-peh

R' Feldman writes

As the Leshem cited above says, if even regarding matters which are not related to halacha, the Sages say, sod Hashem liyerav, “G-d reveals the secrets of nature to those who fear him,” then certainly there must have been siyata dishmaya (Divine assistance) and even ruach hakodesh (a Divine spirit) assisting the Sages in their redaction of the Oral Law. It is therefore inconceivable, to these opinions, that G-d would have permitted falsities to have been transmitted as Torah She-be-al-peh and not have revealed His secrets to those who fear Him.

In other words we have to believe that Chazal got their science from Torah because how could Hashem have hidden these things from them. Hashem would not have allowed them to transmit falsities as Torah.

However this just moves the question to the next stage. No one denies that the remedies found in Chazal don't work today. R' Feldman himself offers the following answer:

The most widespread explanation offered for this is nishtanu hatevaim, “nature has changed” - cures that worked in the times of the Talmud are no longer effective.

If we think about it we can ask exactly the same question that he asked above about nishtanu hatevaim. Is it conceivable that Hashem would reveal scientific facts in Torah and then change nature to invalidate that revealed Torah? Moreover, if he did that, would he do so without telling Chazal (after all Chazal in their scientific pronouncements never even hint that things will change)? Would Hashem put Chazal in a position where they wrote things down in the Gemara (e.g. remedies) as part of Torah Shebaal Peh that are no longer true?

Bottom line, using his logic, how could it be that hashem didn't reveal the secret that nature was going to change? How could he have allowed Chazal to put remedies and other scientific facts in the gemara that were going to change?

VII. His Proofs: Kabballa

R' Feldman writes:

One of the most powerful reasons why R. Avraham’s opinion was rejected by most opinions, is the introduction of the wisdom of Kabbalah of the Ari Zal in the sixteenth century. This cast the Sages in another dimension.

For a more detailed rebuttal see Is Kabbala proof that Chazal could not make mistakes in science?

The Ramban who was one of the greatest Rishonim, was also according to everyone, a great mekubal. And yet, the Ramban, in at least 1 place in his commentary on Chumash (Tazria 12,2) implies quite clearly that Chazal could make mistakes in science. The Ramban clearly and unequivocally records the opinion of the Greek philophers who argue on a scientific fact of Chazal even though the Ramban was one of the greatest mekubalim. We see clearly that kabbala did not teach Chazal science and that the Ramban (who was not from the rationalist/philosphical rishonim) also holds that Chazal could make mistakes in science.

VIII. Is the opinion of the Rambam etc. a minority opinion?

For a more detailed rebuttal see Is the opinion of the Rambam etc. a minority opinion?

R' Feldman writes

In countless places where the commentaries, whether Rishonim or Acharonim (Early or Later Authorties), are faced with a contradiction between the science of their times and a statement of the Sages, they commonly apply the principle, nishtanu hateva’im (“nature has changed”).1 Had they held R. Avraham’s view, they would have simply explained that the Sages erred in following whatever was the medical or scientific opinion of their times.

The premise of this proof is that saying that Chazal made a mistake in science is a simpler and more compelling answer then nishtanu hateva’im. Otherwise there is no proof, the Rishonim answered nishtanu hateva’im because it was a better answer. Therefore it must be that saying that Chazal made a mistake in science is a simpler and more compelling answer then nishtanu hateva’im.

This gives us an insight into R' Feldman's thinking. Even according to him it is more logical to say that Chazal made a mistake then nishtanu hateva’im.

Now we need to ask is his premise correct? For us living in 2005 it certainly is for the following reason. On one hand, we know that the science of Chazal's time was bogus and completely wrong, on the other hand we know that nishtanu hateva’im is difficult from a scientific perspective. therefore to us it makes much more sense to say chazal made a mistake.

However, if we look at it from th Rishonim's perspective the picture changes completely. I believe that for the Rishonim nishtanu hateva’im was a more compelling answer then saying Chazal made a mistake in science for the following reasons:

1. The science of the Rishonim was the science of Chazal. Science progressed little if at all from 300 to 1300 and in Christian countries may have regressed. Therefore, the Rishonim would have no reason to doubt the science of Chazal, they relied on the same science and they believed it was true.
2. Nishtanu hateva’im made sense from their perspective. The rishonim did not understand the world from a scientific perspective and they did not see the difficulties inherent in saying nishtanu hateva’im, in fact, it probably fit in with their world view.

Given the above, Tosafos Moed Katan 11a when faced with the statement of Chazal that rotting fish is healthy vs. the reality that it is not had 2 possible answers:
1. The science that Chazal used was wrong
2. nishtanu hateva’im

I believe that from Tosafos's perspective the second answer is more compelling. They had no reason to doubt the science of Chazal, it was their science.

R' Feldman writes they would have simply explained that the Sages erred in following whatever was the medical or scientific opinion of their times. Than answer to this is very simple, the scientific opinion of Chazal's time was by and large the same scientific opinion of the Rishonim's time.

R' Feldman projects the attitudes of someone living in 2005 who knows that the science in Chazal's time was wrong to the Rishonim. However, the Rishonim had a completley different perspective on science.

IX. Some general questions

1. How come the Science from Sinai exactly matched the Science of Chazal’s day? Isn’t that a bit strange? For example Chazal's description of the Sun revolving around the Earth and going out a window matches almost exactly the Greek view of things.
2.Did Chazal not know that G-d planned to change the Tevah? Or were they just forbidden from revealing it? If they knew, how come they didn’t mention it? If they didn’t know, how come? Didn’t G-d reveal all knowledge to Chazal?
3.If nature changed, how come no one else noticed it? Why is there absolutely no record in the non-Jewish world of any of these changes?
4. R' Feldman quotes RSZA that the shita of R' Avraham Ben Harambam should be quoted as a Yesh Omrim. We see clearly that RSZA allowed the shita to be quoted in a sefer and therefore he clearly held that it was not kefira.
5. If we take R' Feldman's argument to it's logical conclusion we should have to get rid of the Rambam, Ramban al Hatorah, Pachad Yitzchak, R' Hirsch, Michtav M'Eliyahu, etc. After all, these sefarim all have kefira written in them and we are not allowed to have kefira in our houses.

X. Conclusion

I believe that I have shown that R' Feldman's proofs are no proofs and in fact he raises more questions then he answers.

I would suggest the opposite approach to R' Feldman. We know that there is a big dispute when צאת הכוכבים is. The Geonim understood that it is approximately 18 minutes after sunset and R' Tam understood that it is much later at least 72 minutes after sunset. After R' Tam stated his opinion, the majority of Rishonim paskened like R' Tam. The Shulchan Aruch, the Rama and most of the early Acharonim paskened like R' Tam. And yet, alomg came the Gra and said החוש מכחיש, reality contradicts R' Tam and he therefore went back to the pask of the Geonim. In fact, today in Israel the Gra is the accepted opinion בין לקולא בין ךחומרא. Why did the Gra do this? Because החוש מכחיש, reality contradicted R' Tam.

IMHO, החוש מכחיש those opinions who hold that Chazal did not make mistakes in science. Science has progressed tremendously since the times of the Rishonim and the questions that we have today they did not have. Therefore even if the accepted psak was like those Rishonim who held that Chazal did not make mistakes in science (in truth, I am not convinced of that), now we need to pasken like the Rambam et al. who hold that Chazal made mistakes in science because החוש מכחיש that the other Rishonim were wrong and the Rambam et al. are right. I understand that no one today is on the level of the Gra, however, Yiftach B'Doro K'Shmuel B'Doro. This was clearly the approach of R' Hirsch and probably the approachof R' Dessler, if they were allowed to hold that way why can't we?