A. Thank you.
B1. Could you please clarify why? On the Torah level, is he not like someone lacking only the lifting of a finger?
B2. Many thanks. I’d like to ask something a bit vague: is it clear that he is not entitled because he is in fact wealthy, and there is no point in spiritual definitions of what is “his,” but rather in practical definitions—whether he can buy himself food and the like? Or is he always truly destitute, except that there is an external rule that since it is within his power to become wealthy, he is forbidden to take gifts for the poor.

B1. I didn’t understand.
B2. I don’t see any point in this hairsplitting.

B1. On the Torah level, he is allowed to do the act and become wealthy, and therefore from the perspective of Torah-level gifts for the poor he is like someone who on his own decided not to lift a finger and become wealthy. Is there proof that Torah law recognizes barriers created by rabbinic prohibitions? Or is no proof needed?

For example: his father said to him, “Bring me a cup of tea.” There is one cup of tea available for free, but to get to it he would have to violate a rabbinic prohibition. There is another cup of tea that costs 1,000 shekels. The father has no money. And let us assume that the commandment of honoring one’s father is paid for from the father’s funds. Does the son say: “I cannot violate a rabbinic prohibition, and I am not obligated to pay 1,000 shekels, therefore I am not obligated to bring any cup at all”? Or from the Torah perspective is he obligated to go and bring the free cup of tea, and the fact that from his own perspective he has a problem of a rabbinic prohibition is his own problem, so that because of that rabbinic prohibition he will have to go and bring the cup that costs 1,000?

No proof is needed. The barrier here is measured on the factual plane, not the halakhic one. Just as causing someone to violate a rabbinic prohibition falls under the Torah prohibition of “do not place a stumbling block,” because in the end you caused him to stumble in something harmful. And likewise the Talmud in Shevuot 18 (and Rashba there): one who has relations with his wife close to her expected menstrual time and she sees blood is considered inadvertent, not coerced, even though expected menstrual cycles are only rabbinic.

[As to whether causing someone to violate a rabbinic prohibition is a Torah prohibition—I saw on Wikiyeshiva, in the entry on “do not place a stumbling block,” that Tosafot in Chagigah 18a, s.v. “Cholo,” hold that this is not a Torah prohibition. But I looked there, and the proof from Tosafot seems dubious to me.
Tosafot there write that labor on the intermediate days of a holiday is rabbinic. The Gemara in Avodah Zarah 22a says that causing a Cuthean to do labor on the intermediate days of a holiday is “do not place a stumbling block.” This bothered Tosafot. Apparently, Tosafot understood that there is no “do not place a stumbling block” with regard to rabbinic prohibitions. That, apparently, is what the Wikiyeshiva article understood.
But from Tosafot’s answer it seems to me that this was not what bothered them. Tosafot answer that labor on the intermediate days of a holiday is indeed rabbinic, but it has support from the Torah and the Sadducees/Cutheans acknowledge it. But apparently it is not clear how that resolves the issue. In the end, it is still a rabbinic prohibition, so if there is no “do not place a stumbling block,” what difference does it make whether the Sadducees acknowledge it? Therefore it seems that Tosafot understood that if the Cutheans think a rabbinic prohibition is nothing, and in their view it is completely permitted, then there is no “do not place a stumbling block” in this. And that is why the Gemara was difficult for them. To this they answered that the Cutheans do acknowledge that this rabbinic prohibition is truly forbidden, and therefore the Cuthean may stumble into labor on the intermediate days of a holiday. Therefore there is indeed “do not place a stumbling block” here.
If anything, I would derive from Tosafot a nice novelty: that there is no “do not place a stumbling block” where the other person holds, as a matter of Jewish law, that the thing is permitted, even if in my opinion he is mistaken. But you could still say that one who causes another to violate a rabbinic prohibition, where that person acknowledges that rabbinic prohibitions are binding, violates the Torah prohibition of “do not place a stumbling block.”]

This is obvious as an egg by pure reasoning, regardless of sources. If you cause a person to stumble by giving bad advice, that is a Torah prohibition; a rabbinic prohibition is no less than bad advice. And that is also implied by the Rema in Yoreh De’ah regarding witnesses to a loan involving the dust of interest, who violate “do not place a stumbling block” (and simply speaking that is Torah-level).
True, the medieval authorities apparently disagree about this in Avodah Zarah 22a, Tosafot s.v. “Tipok.” See there Tosafot, Nachmanides, and Ran. But I saw that Rabbi Y. Tz. Raymond explained very well that this is only where the transgressor knows there is a prohibition involved. But when he does not know, it is obvious that there is a Torah prohibition here. See his words here: http://asif.co.il/?wpfb_dl=1439 section 5.

As for the nice novelty you mentioned, see Ritva on Sukkah 10b at length, and Rashi in the Chullin 11 passage “Heaven forbid for Abba bar Abba,” which is mentioned in the Ritva there. And an explanation of his words is in my article “Is Jewish law pluralistic”: https://mikyab.net/%D7%9B%D7%AA%D7%91%D7%99%D7%9D/%D7%9E%D7%90%D7%9E%D7%A8%D7%99%D7%9D/%D7%94%D7%90%D7%9D-%D7%94%D7%94%D7%9C%D7%9B%D7%94-%D7%94%D7%99%D7%90-%D7%A4%D7%9C%D7%95%D7%A8%D7%9C%D7%99%D7%A1%D7%98%D7%99%D7%AA

How wonderful this place is! I looked into all of the above and had the privilege of real satisfaction.

A. Rabbi Raymond’s reasoning there—that if the transgressor knows it is a rabbinic prohibition, then the “do not place a stumbling block” on the one causing him to stumble is only rabbinic—I do not know what “very well explained” you found in it; it is nothing but astonishing to me (especially according to Netivot, for whom an inadvertent violation of rabbinic law is nothing at all. Though Cutheans are actually rebels against rabbinic authority, and one could analyze that). But below I will write a similar idea in Ritva, and there it is indeed understandable.

B. The view of Ritva in Sukkah is that one who holds “permitted” may hand it to his fellow who holds “forbidden,” provided the latter knows. And you took this as support for monism that recognizes autonomy. But that is hard to accept unless the Gemara explicitly compels it—what does it mean to recognize the autonomy of an error that causes a sin against the will of the Holy One, blessed be He?
But one can understand it in a somewhat similar but different way, along the lines of Rabbi Raymond’s reasoning. Autonomy makes the matter fully permitted, because if a person relies on his own opinion, then for him it is fully permitted, and the Holy One, blessed be He, does not come with demands against His creatures—what else could he have done, since he truly thinks it is permitted according to Jewish law? But when he does not know (as opposed to knowing that it is permitted), then he is like other inadvertent sinners. That is: there is indeed one monistic truth, except that autonomy also makes the other opinions into equally complete truth. And there is never any justification for helping one’s fellow violate a prohibition according to my own view.
Now then, since the guests see that the decorations are extravagant, if they think it is forbidden, they will not sleep there. And if the rabbis retracted their ruling and they think it is permitted, then they will sleep there. And there is no need to worry that these two golden pitchers will fail and intentionally violate that prohibition (just as one may hand someone a cup of water on the Sabbath and need not worry that he will run to the garden and water seeds).
Your meaning in that article is not clear to me—does autonomy make it permitted, so that from the perspective of the Holy One, blessed be He, he is exactly, exactly like me (while I follow the true monistic Jewish law), in which case I have merely repeated what you wrote there? Or does he in fact stumble into a prohibition and damage the upper worlds and plague his soul with a terrible plague, and the Divine Presence cries out “My head is heavy, My arm is heavy,” and the angels of peace weep bitterly, and trembling and dread seize them—except that there is some side-value called autonomy, by whose name we will absorb all the damage in the world?

(By the way, I had read the article you referred to about pluralism in Jewish law at some point. And probably because of that it was easy for me to think, as above regarding Tosafot in Chagigah, that it is permitted to hand something to one who holds it is permitted. I even felt there was something important here, but I couldn’t put my finger on its nature. And now that the matter and its significant implications are all there in the article, well explained, I understand in retrospect where these ideas sprouted in my head so easily, as though they had come from me, and the feeling I felt as though I had felt it on my own, etc.)

And a practical implication of all this concerns autonomy to commit a value-based wrongdoing, such as autonomy to eat meat. For if autonomy in Jewish law exists because the Holy One, blessed be He, waives and permits it to one who thinks it permitted (as I suggested), then there is no room for autonomy in morality (and that is indeed what I think. Granting autonomy is a lazy, utilitarian, anti-value, wicked arrangement, though without it life in this world would be impossible). But if it is because there is real substance to a value called autonomy, then even in morality—where there is no higher conscious being who can waive His wishes, etc.—there is still room for autonomy.

It seems to me that I explained everything and answered everything, and these are simple and necessary points. I’ll comment briefly on your remarks:
1. Rabbi Raymond’s reasoning is simple: a rabbinic prohibition is no different from advice that is improper.
2. And none of this has anything to do with Netivot, because when the one causing the stumbling is intentional and the one stumbling is inadvertent, that is still a sin for the one causing it, along the lines of Maimonides, Laws of Diverse Kinds, and the parallels. Besides, as is known, many disagree with Netivot.

3. Autonomy in morality is altogether a strange discussion, since a moral wrong has consequences for others—what room is there for autonomy in that?
4. Your reading of the Ritva—that there is no concern they may intentionally stumble into the prohibition—is certainly not the Ritva’s own view, since he derived from here a general rule in the laws of causing another to stumble, and did not limit it only to righteous people.

Nothing is simple, and certainly not “obvious as an egg.” I don’t know the color of red cabbage without proof from Rashba in a responsum. I don’t understand these words.

1–2. Rabbi Raymond says that if the one who stumbles does so intentionally, then the one causing him to stumble violates only a rabbinic-level “do not place a stumbling block,” whereas if the one who stumbles is inadvertent, then the one causing him to stumble violates Torah-level “do not place a stumbling block.” What is simple about that reasoning, and what is “very well explained” about it? God knows.
4. The Ritva there writes: “Here specifically because the prohibition is recognizable to his fellow, and if he does not hold that way, he will not eat.” There is no strain at all in explaining that if one fears his fellow may be seduced and fail and eat even though he does not hold that way, then it is forbidden to hand it to him. Exactly as I said.

And from what I see in Maimonides, Laws of Diverse Kinds chapter 10, law 31, it seems to me not relevant to the matter, but this is not the place.

On fourth thought, I understand that your interpretation of the Ritva is better. Even though it still bothers me why he didn’t explain it the way I said. Thank you, and sorry.