But you yourself defined mysticism as something esoteric that is not accessible to everyone. That is, you did not define mysticism as something we simply do not yet understand. So according to your definition, Acamol does not fall under mysticism and esotericism, even before its invention, because theoretically the way it works is accessible to everyone; we just had not yet understood how.

Who told you that? As long as you do not understand how it works, how do you know what its mechanism is? That is exactly the practical problem I described.

Even if I do not know how it works, that does not mean it is accessible only to a select few. String theory could also fall under that definition, and no one says that is mysticism. Besides, if you claim that everything whose workings we do not understand is mysticism, then why did you not define mysticism that way, but rather in a different way?

Where did I write that what we do not understand is mysticism? I was not dealing here at all with the definition of mysticism. I argued that there is a practical problem with the approach that holds there is something real in other powers (from the “other side”), namely: how do we know whether something that works comes from this side or that one?
What I wrote here is that as long as we do not understand how Acamol works, we have no way of knowing whether it is mysticism or not, meaning whether it has a natural explanation or not. You wrote that of course it does, and about that I wondered how you know.

The Baal Shem Tov, or one of his successors (I could make the effort to find a source), defined closeness to the Holy One, blessed be He, in accordance with love of one’s fellow, and the reverse as well. That is, the masters of mysticism found characteristics in the more familiar world as indicators for identifying service of God or service of the “other side.”

Okay, so I will suggest a different formulation for the prohibition:
Anything that is definitely connected to the esoteric (that is, there is no reasonable possibility of attributing it to something natural) is forbidden even if it works.

How do you know with certainty that it is esoteric?

By the phrase “definitely esoteric” I meant a phenomenon for which there is no reasonable basis for attributing it to a natural mechanism of action.

You tried to offer a criterion regarding what is forbidden and permitted. I do not see a criterion here. Anything whose mechanism is unknown could be esoteric or not. In most cases I can think of, we have no way of knowing. In the lecture itself I said that perhaps with the use of a proven amulet one may assume that it is mystical, because it has no chemical or biological interaction with our body (setting aside the placebo effect, of course, though it is fairly hard to believe they accounted for that in the time of the Talmud).

Beyond that, according to the approach of Nachmanides and those aligned with him, it is hard to accept that what was forbidden is mystical healing and that only natural medicine was permitted. They distinguish between two kinds of mystical healing: through holiness and through powers of impurity. Therefore there is a discussion about violating a prohibition (such as desecrating the Sabbath) for the sake of mystical healing, implying that without a violation there is no prohibition in it per se.

Why is there no criterion here? True, anything whose mechanism is unknown could be esoteric or not, but as long as one can reasonably imagine that there is a natural explanation, it does not fall under my criterion. Only things for which one cannot reasonably imagine a natural explanation are forbidden, and only those are forbidden, even if they work. I am not trying to claim that this is the view of Nachmanides and his camp; I am trying to propose my own coherent criterion for the commandment “Be wholehearted.”

I asked about the view of Nachmanides. You are proposing your own approach, but it is unnecessary. There is the view of Maimonides.
Beyond that, I do not understand how you know whether a natural explanation is possible or not.

The view of Maimonides is empty of content, because if someone thinks something works, then it is permitted, and if it does not work, then in any case there is no point in using it. I am not saying that it is impossible, only that a reasonable person perceives the thing as mystical.

I just now saw that in an old question about turning to wonder-working rabbis, you wrote this:
“In my opinion such appeals are Torah prohibitions. Beyond that, I estimate that these people have no abilities whatsoever.”
It follows from your words there that even if they do have abilities, there is still a Torah prohibition involved (not like the view of Maimonides). That does fit the approach I suggested. How does that square with what you explained in the lecture?

If they have abilities, that depends on the dispute among the medieval authorities (Rishonim). According to Nachmanides there would apparently be a prohibition here. But its parameters really still require further analysis. I said that something like amulets or incantations can perhaps be assumed to be mystical-esoteric, because there is no chemical interaction with the body.

But if I understood you correctly from the lecture, you hold like Maimonides—that whatever works is permitted, even if it is mystical/esoteric. If so, how does that fit with the answer about the wonder-working rabbis?

Because according to my own view, I hold that they have no abilities. But I added that even on the possibility that they do, the view of Nachmanides and most of the medieval authorities is that there is a prohibition in this. Especially since they themselves claim that they are not doing it by way of nature.

Let us set aside the view of Nachmanides for a moment. I am asking according to your own halakhic view, in a case where there is some wonder-working rabbi who truly has effective abilities. Would it be permitted or forbidden to turn to him?

According to my view, one would need very strong evidence that he has powers, and it is doubtful how far such evidence could be supplied without a very thorough examination. If he passes a strict test, then in my personal opinion it is permitted to turn to him.

Why do you choose specifically to adopt the view of Maimonides and not an approach like the one I suggested, namely that even if something works, as long as it has a distinctly mystical/esoteric character, it is still forbidden?

Because in my opinion there is no such thing as powers of the “other side,” even if there are mystical powers that are not natural.

I did not say in my suggestion that there are powers of the “other side”; I only said that we are dealing with something supernatural that is forbidden even if it works.

I do not see any logic in prohibiting the supernatural simply by virtue of its being supernatural, unless it expresses powers of the “other side.”

The logic is that people can end up creating a personality cult around that “baba” who has mystical abilities. In other words, once they see that he has mystical powers, they will tell themselves that only a righteous person, or someone desired by the Holy One, blessed be He, could have such powers; and because of that they will listen to what he says as if to say, “look at this and sanctify it.” And that same baba, who suddenly sees that people are making pilgrimages to him, will let it go to his head, and he will start thinking that maybe he really is a righteous person and that the Holy One, blessed be He, chose him to have these abilities. From there he may come to challenge the sages, or perhaps even the Sages of the Talmud. And indeed we do see problematic phenomena around such “babas” and around various Hasidic courts.

So that is a Torah-level safeguard. I would expect people not to see this as such a severe prohibition, and certainly not as an accessory prohibition of idolatry. After all, if he has such abilities then he really is a person of stature. To turn appealing to him into such a severe prohibition only because of those concerns is very strange.

But even according to your view, or the view of Maimonides, I would expect people not to see this as such a severe prohibition,
and certainly not as an accessory prohibition of idolatry. After all, it is just a foolish act. There are many foolish things people do every day, and there is no prohibition on them.

Every prohibition of idolatry is like that; basically it is a prohibition against being stupid. Apparently stupidity is a very serious matter according to Maimonides (and I agree as well). You can also see nowadays where such things lead.