Sunday, March 14, 2010

Eating meat and fish together


We have explained that the Torah requires us to guard our lives, and so we stay away from dangerous foods.

The sages understood that eating fish and meat together, or even cooking them together such that vapor from one could invade the other, is dangerous.

(Shulchan Aruch Yoreh Deah 116:2)

Have a great day,


  1. I often struggle with this kind of thing. I know that, when it comes to medical remedies, we're advised to refer to the best medicine/science of the day. Presumably, it is because chazal's understanding (then) of the medical care needed now, was/is not accurate. I'm not sure why we don't feel the same when we read of concerns that the mixing of fish and meat vapors could be dangerous to our health. Do we actually believe it is dangerous? Or, do we defer to the considered opinions of Chazal here (though not on all areas of medical advice)and follow those opinions because of the primacy of Chazal? Is the question clear?

  2. Hi Michael,

    I believe your understanding - that we go with modern science - is correct. However, we tend to apply that more to adding health risks, rather than removing old ones, out of concern that we don't have all of the information regarding risks.

  3. Good evening,

    Isn't it true that in neither adding new risks nor removing old risks, do we have all of the information? So, it would seem that if we were were convinced of the wisdom, brilliance and insight of the chazal, we would adopt their views no matter what. Even if something flew in the face of modern science we should expect to find some hidden wisdom in their observations and recommendations.

  4. Hi Michael,

    Not sure what you are recommending here. Are you suggesting that we would then not add new risks in light of purportedly new information?

  5. I think my underlying question is something like the following(at the risk of sounding heretical, though I know you don't view me that way): If Chazal missed the mark on medical remedies, isn't it equally possible (or even likely) that have it wrong on things like the dangerous effects of mixing fish and meat vapors? I would imagine that we would have a hard time finding the science to confirm the toxicity of this mixing. In the absence of evidence, is it at all reasonable to assume Chazal is mistaken and therefore the decree is incorrect? I really do not mean to be disrespectful. I hope you'll appreciate that.

  6. Hi Michael,
    No, not heretical, as I see it.
    But the fundamental point is that in health matters, we don't assume we have all of the information. Just as I stay away from certain products because some physicians believe they are harmful, so I stay away from foods that chachamim said were harmful. The cost to me is low, and the potential benefit is high.

  7. It's interesting to look at it that way. It leaves open the possibility that Chazal were wrong, but that the harm/benefit equation of acting in accordance with Chazal favors following them. An alternative response that I have heard (and continue to hear very often) goes something like: "Chazal couldn't have been wrong." -- thereby commending one to act in accordance with Chazal. In either case, one acts/rules according to Chazal, but the reasoning behind that decision differs in each of those two situations. It doesn't appear to be an "either/or" situation. Your thoughts?

  8. Hi Michael,
    Yes, that philosophy is familiar and authentic, and dates back at least to the Rashba on identifying animals as tereifos. At the same time, there are serious halachic authorities who contend that when it comes to practical halachah, we do not adopt the Rashba's view.

  9. Good evening,

    I'm not sure I understand the Rashba's view. Does the Rashba hold the view that: Chazal might have been wrong, but one should follow Chazal because the consequences of not following them might be great -- or did he hold that Chazal could not have been wrong (with regard to halacha)?

  10. Hi Michael,
    Rashba's position is that the chachamim are not wrong.

  11. I know we're getting close to Pesach and the time available for corresponding is extremely limited. Residual question: For the Rashba, Chachamim couldn't have been wrong. Therefore one must follow their psak din in all areas. For those who believe that the Chachamim could have been wrong (at least on practical matters), on what basis would they believe they could have erred? Is it, "The Chachamim are people and people make mistakes." But, if that's the argument, then why would those mistakes be limited to the practical matters and not the theoretical/spiritual ones? And if mistaken in some areas, in which areas would those be, (certainly not all practical matters)?

  12. Hi Michael,

    Thanks for your email. I would think it far more likely that a chacham err in zoology, which he has not formally studied, than that he err in Torah, where he has studied and demonstrated brilliance.
    Rashba can read a gemara in Chullin and challenge it from Uktzin and bring a resolution from Zevachim with support from Kilayim - that shows that he knows Torah far better than I do.

  13. Moed tov,

    I really appreciate your willingness to engage in this way. I hear what you say with regard to using one's "rational" or "common sense" or, call it, intuition. That is, (and I agree) that it's more likely that the Chachamim are versed in Torah than zoology. But, from an epistemologic standpoint, can one site a source that would tell me, Michael, (from an intuitive viewpoint), that it's more acceptable to challenge Chazal's biology than theology? Or, are we simply applying "lo b'shamayim hee"? As soon as I can claim something like: "I don't think that Chazal possessed the expertise to ..."-- it sounds like it opens up many possibilities, many of which we would not welcome.

  14. Hi Michael,

    How about shabbat 85a, in which the sages learn agriculture from Canaanites?