Q&A: Jewish Law and Science
Jewish Law and Science
Question
Hello Rabbi,
I would like to ask about the Rabbi’s view regarding how the Sages determined Jewish law. Does it seem to you that they determined it according to the scientific tools available to them, and that with today’s advances there is also room to change the Jewish law? I’ll explain by way of examples.
First example: if science were to determine that when metal utensils and the like are heated to 300°, all food particles are burned away, and this still would not count as intense libun, would that be enough to render them fit? (For Passover or for other matters.) What I want to ask is whether, in your opinion, the Sages established the laws of libun before they knew the science, or whether there is some meta-halakhic consideration and determination here that is not dependent on objective physical science. (Which, by the way, would not be a problem.)
Second example: if it were proven that blood resulting from the tearing of the hymen is in no way connected to uterine blood, and there is no such concern (theoretically), then is there no room to be lenient regarding the stringency of counting and examinations, rabbinic impurity (apparently because of doubt. That isn’t actually stated in that Talmudic passage; it just occurred to me off the top of my head), and to permit her as one permits a woman who is definitely seeing blood due to a wound while otherwise pure? (Not that I know of such a rule in the words of the Sages.) Or again, is this a meta-halakhic determination and not merely a scientific one?
Thank you, and may we hear good news.
Answer
The Sages established Jewish law according to factual-scientific judgment to the best of their knowledge, together with formal criteria (so that the matter would be simple and unequivocal). In a place where the facts are clearly incorrect, I assume the Jewish law can be changed. Where the matter is not unequivocal, there is no way to change it, because something established by a formal count requires another formal count to permit it.
For example, only today I was asked about the absorption of nourishment by a perforated flowerpot, and I said that since there is no quantitative measure for how much it has to draw, I do not see a way to change the Jewish law based on current scientific findings.
Regarding the examples you brought:
1. If they are completely burned away, there may perhaps be room to permit it, but that is only if the rule is sweeping and always true. As stated, the Talmudic rule was also established so that the Jewish law would be simple and uniform, and therefore in principle intense libun is required. To change that, it would have to be clear that in all utensils and situations there is another way to do it. If this is true only in certain situations, that is not enough.
2. Here too, the same applies. If it is scientifically clear, and in all cases there is no problem, then there is room—and it would even be appropriate—to change it.