Q&A: Coherence Regarding Jewish Law and Science
Coherence Regarding Jewish Law and Science
Question
It is commonly accepted to view the Babylonian Talmud as decisive halakhic authority, and today the Shulchan Arukh as well, while the answer given for this is vague and circular: they have authority because they were accepted as having authority.
Let us ignore for a moment the problem with that vague and circular answer, and adopt the thesis that indeed the Babylonian Talmud and the Shulchan Arukh are the halakhic authority, as if this were a law given to Moses at Sinai.
My question is a different one: the overwhelming majority of the laws, in all their details, are based on mistaken scientific facts. For example, all the laws of mixtures and salting are based on faulty chemistry: “the lower one prevails,” “since it is occupied with absorbing, it does not emit,” “as it absorbs, so it emits.” All the laws of ritual baths are based on the idea that spring water is not rainwater, and so on.
There is a well-known answer in the name of the Chazon Ish that even if the Sages were mistaken, the Jewish law follows them.
The problem is that this does not fit the entire halakhic give-and-take of the Jewish bookshelf throughout the generations.
When I study a Talmudic passage, I see that all the medieval authorities and later authorities relate to the Sages and to factual truth as corresponding to one another. And when some factual truth seems, in their view, to contradict the Sages, they strain and reinterpret the saying of the Sages, saying it refers only to such-and-such a case, and that is how it is ruled in practice. But today this is impossible, because in practice it would nullify most of the laws and most of the enormous Jewish bookshelf.
It seems as though until recently people tried to fit known reality to the Sages, and we interpreted the Sages in a way that would not contradict reality, with all the halakhic implications involved. Lately, when factual knowledge has become clearer than ever, while on the other hand the rabbinic decisors have not had the wisdom to recognize this, a situation has arisen in which factual knowledge is almost entirely ignored.
Today, in practice, people usually follow the Sages, whether leniently or stringently. Leniently, for example, in eating salted meat even though it still contains blood; in not prohibiting bloodstains even though today there are no fleas; and so on. Sometimes people act stringently in accordance with reality, for example by forbidding the killing of a louse on the Sabbath and forbidding the eating of worms that are supposedly generated between the skin and the flesh and do not reproduce. Sometimes they are even lenient in accordance with reality, for example regarding an eight-month infant not being set aside on the Sabbath.
In short, I see here an extreme lack of coherence.
1) Halakhic decisors, in practical rulings, almost always relate to the Sages and do not even bother to know the reality on the matter, but in the books of the medieval authorities and later authorities there is constant reference to reality.
2) Sometimes they are stringent in accordance with reality; this usually happens in matters where the reality is already obvious to everyone and emotionally hard to ignore, but there is no clear halakhic principle behind it.
3) Sometimes they are lenient in accordance with reality in an extreme case, like an eight-month infant on the Sabbath, and it seems to me that even if today such an infant had no chance of surviving, nobody today would rule that he may be left to die of starvation because of the laws of set-aside items.
The question is whether you have a coherent method for explaining all this?
Answer
- I don’t think one needs to explain everything that is practiced in Jewish law. There are foolish customs.
- I don’t think you are right that most of Jewish law is based on factual errors. In my opinion that is very far from the truth.
- Even in the examples you gave, regarding fleas this is not a matter of probability assessment (that is, that most likely it is a flea) but of assigning it to an exceptional possibility. Like the concern for a twelve-month pregnancy. The claim is that where there is no certainty, the Sages did not prohibit it, and any exceptional possibility, however remote, is enough to permit it. Therefore, the fact that today there are no fleas does not matter for this issue.
Discussion on Answer
If your question is about the examples, one can discuss each of them individually (some are correct and some are not). But your question was about Jewish law as a whole, and a few examples prove nothing about that. What you brought is a negligible and insignificant minority of the totality of the laws. If you go through the Shulchan Arukh or Maimonides, you will see that this is a tiny part of Jewish law.
On the same topic—regarding “a primary vessel and a secondary vessel”…
The Talmud and the halakhic decisors ruled that “a primary vessel cooks” and “a secondary vessel does not cook”…
And they accepted this as a rule, without checking in each reality whether to define it as cooking or not…
There are some decisors who added laws and qualifications which, in my view, stemmed from the gap between the rule and reality—the view of the Chayei Adam regarding “so hot that the hand recoils,” Maharshal regarding a solid block, and similarly the Chazon Ish when he is lenient regarding “easily cooked foods” according to “what our eyes see,” but stringent regarding a tertiary vessel (because that is even harder to understand)…
These laws were not established on the basis of interpretation of Talmudic passages. Apparently they reasoned that one cannot go quite so far with the rules… but on the other hand these qualifications too were made in the form of setting rules, and at least over time they become rules that are not necessarily connected to the factual definition of cooking, which has many more nuances. (It would have been possible to set a principle regarding cooking, and then we would need to discuss each case of reality.)
What is the Rabbi’s opinion on this subject? Once it was ruled in the Talmud that we accepted it, did it become a “formal rule” that a primary vessel does not cook? (The words of Maimonides regarding the laws of non-kosher animals are well known.) If so, then seemingly there is no room to create these qualifications without a source in the Talmud…
And on the other hand, if we seek a factual definition, these rules too are not enough… (and many things that are permitted today would then be prohibited)…
How does the Rabbi conduct himself on this matter?
It seems to me that in a place where it is clear that even the Talmud was aware that there is a gap between the halakhic determinations and reality, then clearly one should follow the Talmudic rule. But if the determination was based on an error from the outset, there is room to cancel it. And even when one follows the Talmud, there is room to qualify it or interpret it narrowly in situations where it leads to absurdity.
The questions are not only about these examples, but I would be happy to get an answer on them so that I can understand the general approach.
Also, what is the Rabbi’s opinion regarding meat that was salted and still has blood left in it (blood always remains)? In reality there is no such thing as “the redness of meat,” and the blood molecule is identical.
That is a good example. Nobody claims that the molecule is different. But blood that underwent koshering is no longer considered blood. Precisely because blood always remains, they were forced to say that the blood that remains is permitted.
Thank you for the quick answer.
I think that most, or at least a very large part, of the details of Jewish law—that is, the critical mass of halakhic discussion—is based on factual mistakes.
Just for example, very briefly:
1) According to your approach, can we close the books on all the laws of meat and milk and mixtures, and rule according to the chemistry known to us today? Meaning that all the pilpulim about “a sharp substance,” “fatty,” “enough for peeling,” and “the lower one prevails,” “since it is occupied with absorbing, it does not emit,” “as it absorbs, so it emits” are irrelevant today when all this can be tested in a lab? (And I have a feeling that 99 percent of it is simply not correct.)
2) How do you explain the halakhic difference between spring water and rainwater, when in fact the water of a spring is rainwater? Nor can one force a weak answer that the seepage of rainwater through rock qualifies it to be called a spring, since in the Talmud there is a discussion whether after rainfall it is permitted to immerse in a spring because perhaps most of its water now comes from rain and not from its source—but today we all know that all spring water is rainwater.
3) The concerns about menstrual cycles are mostly irrelevant today, and some of the calculations were mathematically and statistically incorrect to begin with, such as interval cycles with skipping patterns. So should this whole subject be canceled?
4) Regarding insulation in something that adds heat, it seems to me that the words of the Mishnah do not fit reality. Salt, lime, and sand do not seem to add heat, while fruit does add heat. “These are things that add heat: olive waste or sesame waste, manure, salt, lime, and sand, whether moist or dry, and straw, grape skins, and soft fibers and grasses when all three are moist. And these are things that do not add heat: clothing, fruit, pigeon feathers (or other feathers, Mahar”a in his glosses), flax tow, and a carpenter’s sawdust.”
And the Ramah adds: “Some say that it is permitted to insulate in stones even though they add heat, because the rabbis did not decree regarding something uncommon.” But stones also do not add heat.
5) A sukkah higher than twenty cubits is invalid when its size is four by four, because then one is not sitting in the shade of the roofing but in the shade of the walls. So what if someone sits at noon on the equator, where he is sitting in the shade of the roofing even when it is 100 cubits high? Or alternatively in the far north, or toward evening, where even in a sukkah only ten handbreadths high he is sitting in the shade of the walls?
What if the sukkah is small, or he is sitting right next to the wall? Even in the Land of Israel there is a difference from year to year in the angle of the sun.
And in general, in no calculation do I see why a height of twenty cubits causes a four-by-four sukkah to be in the shade of the walls. I tried calculating for the Land of Israel, during Tishrei, at noon, when sitting exactly in the middle of the sukkah, or any alternative calculation, and no calculation explained to me why specifically these measurements.
6) Quote from the Shulchan Arukh: “But if the roofing is not greater than the open space, but they are equal, it is invalid, because the sunlight entering through the open space in the roofing spreads out more by the time it reaches the floor of the sukkah than it was above in the roofing, and thus the sukkah below, at its floor, has more sun than shade.” In practice, if they are equal in the roofing, the level of direct radiation entering is less than half because of the thickness of the roofing. And if one looks at the percentage of the floor directly illuminated, then on the contrary—even if above it has more shade than sun, below it has more sun than shade, because enough light from part of the sun is sufficient to illuminate the floor.