That wasn’t my question. My question was: according to that, what is the difference between agency without “a person’s agent is like himself” according to Rav Yoshiya, and “a person’s agent is like himself” according to the side that says the agent is not merely an extended hand, but only that his actions are attributed to the sender?

Or in other words, is the conceptual inquiry of the Or Sameach the subject of the Amoraic dispute in Bava Metzia?

And I answered that no. That cannot be the dispute, because otherwise the inquiry would already have been decided in the halakhic ruling among the Amoraim.
I explain in the lectures that there are different planes of discussion regarding attribution of the act to the sender. It can be attributed to him legally or practically. I elaborated in the lectures themselves.

Okay, I don’t understand.
I’ll look in the lectures—do you have a reference, please?

In the lectures you suggest that maybe the first version and the second version regarding “it is more of a commandment for a person to do it himself than through his agent” disagree over whether it is a moral principle or a halakhic one.
The second version would hold that it is moral, since it applies it to the woman, and the woman has no commandment of kiddushin at all.

But seemingly one could say the same thing about the first version. It applies it to kiddushin, which are not commandments, and to preparations for the Sabbath, where there is no agency.
So apparently it comes out that according to both versions the principle is always moral, not halakhic.
No?

A woman does not have the commandment of procreation. As for kiddushin, according to the prevalent view there is no commandment for anyone. And even according to Maimonides it is not certain that it is different.
Even if some act is not subject to agency, that does not mean there is no halakhic principle here. If it is not a commandment, then maybe yes.
I don’t think that was where I ended up in conclusion regarding the two versions.

Tosafot of Rabbi Shmuel bar Yitzhak writes on the Mishnah: “And that which it teaches, ‘the man betroths,’ is not to say that it is permitted ab initio through his agent, but rather to teach us that even though there is a prohibition, the kiddushin take effect.”

And that is difficult for me: if in this wording of “the man betroths” the Mishnah really wanted to teach that even though there is a prohibition, the kiddushin still take effect, then why did it not actually use post facto wording? It could have written: “If he betrothed, whether by himself or through his agent, she is betrothed.”
From its ab initio wording I would infer the opposite—that there is no prohibition at all, because the man betroths by himself and through his agent ab initio.

A valid comment. But maybe according to his approach one can read it as the novelty being that there is a problem, not that the kiddushin take effect: the man betroths by himself, and even through his agent, despite the fact that this is problematic.
One should remember that the Talmud there is not coming to explain the novelty of the Mishnah. The question they answer is why it mentioned him and not only his agent, because if through his agent it takes effect, then all the more so by himself it takes effect. And to that the answer is that this comes to teach that it is more of a commandment for a person to do it himself than through his agent. In other words, that explains why it mentioned kiddushin by himself, not the novelty of the Mishnah in itself, which is that one can indeed betroth also through his agent.

The Ran writes that the woman assists her husband, and by that she performs a commandment, and therefore it is relevant to her that it is more of a commandment to do it herself than through her agent.
And you said, rightly in my view, that assistance is like a result-commandment, and therefore agency is not relevant to it, so it follows that the Ran understood “it is more of a commandment to do it oneself than through one’s agent” as a broad moral principle in the service of God that applies to every good act.

But what is difficult for me is that if so, what was the Ran’s question in the first place—“why is this principle relevant to the woman”—and why does he look for the idea that she assists, etc.? Seemingly he should have written, not asked, that it applies to her because she is now doing a good act of kiddushin for someone.

In the question he thought one had to speak in terms of agency and commandment, and his conclusion is that one does not.

Does it necessarily follow from this Ran that he holds there is a commandment in the full formal sense in kiddushin? Right?

Absolutely not. It is assistance to a commandment-related matter, which for this purpose counts as a commandment. She does not have fulfillment of a positive commandment.

A. According to the view that “it is more of a commandment to do it oneself than through one’s agent” is a halakhic principle, and it applies also to kiddushin, does that mean that it would also hold there is a commandment, in the formal sense, in kiddushin?

B. The Raavad holds that one must go back and betroth again. Does it necessarily follow from that that he holds this principle is halakhic? As I understood from the lecture you gave, one could say a different reasoning: that really he holds that this is a general moral principle, and the kiddushin themselves are not defective, but you did not perform them in the ideal way, and therefore you can, or perhaps even must, go back and do them in a more enhanced manner. That would follow either according to the view that enhancement applies even after performance of the commandment, or one could also say that it follows even according to the view that enhancement applies only at the time of performance of the commandment, except that here the commandment is the result—to live with the woman I betrothed—and therefore according to everyone enhancement is relevant here. But it does not seem reasonable to define kiddushin as a result-commandment; it seems plainly to be an action-commandment.

C. You distinguished between this principle as a moral principle, focused on the person, and as a halakhic principle, where the commandment itself is lacking.
Would it not also be correct to say that even if it is a halakhic principle, it is still a halakhic principle focused on the person, and not on the commandment itself—that is, the commandment itself is complete, but the person’s fulfillment of the commandment is lacking?

The Ketzot HaChoshen wrote:
“And it is fitting to doubt, in a case where he was of sound mind when he appointed him as an agent, and before the agent completed his mission the sender became insane—do we go after the beginning, and since at the time he appointed him as an agent he was of sound mind, the agent stands in the sender’s place, or do we go after the end, and behold at the time the agency was completed the sender had become insane and the agency is void? […] However, one must still consider, according to the view of Maimonides, that his agency is not voided even if he became insane at the time the agency was completed, because the agent had already stood in the sender’s place when he appointed him. If so, regarding what we learned in the first chapter of Gittin (13a): ‘One who says, Give this bill of divorce to my wife, this deed of emancipation to my slave,’ and then dies—they may not give it after death. Why should we not say that the agent already stood in the sender’s place? For a dying person or one who became insane also has no legal effect in his acts, and yet we say he has already been made like him.”

You explained in the lectures that according to the Ketzot, for everyone agency is a power of attorney.
A. If so, according to the Tur, when the get is invalid it is because the insane person is outside the category of divorce, right?
B. If that is what he holds, why does he ask in the “however, one must still consider…” only according to Maimonides and not also according to the Tur?

A. Not necessarily. It could be a halakhic principle that also handles acts that are not themselves commandments but are assistance to a commandment and the like.
B. If one has to go back and betroth, then yes. But maybe he holds that it is advisable to go back and betroth, and then no. There is still a novelty here that such a thing is even possible. Enhancement after the performance of the commandment is not relevant here, because he is going back and performing the commandment itself again, and because here one cannot technically do the enhancement without performing the commandment itself. Enhancement after the commandment is like the fringes of flesh that do not invalidate circumcision, where one can cut them afterward after having already performed the circumcision.
C. Possible. Like sitting in a stolen sukkah, where according to the Minchat Chinukh the law of a commandment that comes through a transgression means that the commandment was fulfilled—meaning, he has not neglected the positive commandment of sukkah—but the person did not perform a commandment.

That Ketzot links the sender’s becoming insane to the sender’s death, and many have already attacked him on that. Most later authorities wrote that even according to Maimonides, if the sender dies the agency is void, because there is no agent without a sender.
A. That is the Tur’s position, with no connection at all to the words of the Ketzot HaChoshen. If the sender became insane and is not legally fit for divorce, then his agent likewise cannot divorce in his name. Not because he is outside the category, but because he cannot divorce. Whatever he himself cannot do, he cannot appoint an agent to do. Maybe that is what you meant by being outside the category of divorce.
B. I didn’t understand what you are asking. The Talmud there says exactly the Tur’s position. What do you want him to challenge the Tur from there?

The mechanism of agency that you called “emptying out”—is that basically just an extreme form of power of attorney, where the agent remains in place and valid even if the sender dies? Right? It is not a novel mechanism, just a type of authorization, yes?

I no longer remember what you are referring to.

A. Is the difference between an agent for delivery and an agent for receipt the difference between an extended hand and power of attorney, or the difference between agency for an act and agency for legal power?

B. Does the distinction between agency for an act and agency for legal power overlap with the distinction between action-commandments and result-commandments? That is, for example, would every action-commandment be one in which the law of agency is agency for an act?

C. What especially troubles me in this topic is that every distinction can be taken in both directions, stringently and leniently. There is no single clear distinction where you say, ah, here we distinguish between A and B, and a hierarchical relation results between them. How do you make the calculations in the topic if everything we say can be taken in both directions? How do you rule in the end? For example, “it can take effect even against his will” is both a positive reason for agency and a reason to deny agency. So how do you rule?

D. There is agency for an act and agency for legal power. What about agency that is neither for an act nor for legal power? For example, agency to write a get. On the one hand, this is not agency over an act—there is no need for the agent to be considered the sender himself, or for it to be the sender’s own body writing the get. On the other hand, it is also not agency for legal power, because no legal effect is created here by writing the get.

A. Act and legal power. Power of attorney or extended hand is a dispute among the medieval authorities in understanding the law of agency, not two kinds of agency.
B. Sounds reasonable.
C. When there is hierarchy in both directions, that is a two-way refutation. You cannot derive either one from the other. Sometimes there is a dispute over which side is more stringent, and then those are two opinions.
In halakhic ruling, one rules on the law, not on the reasoning.
D. Writing a get is agency for legal power. When the agent writes, it is considered that the husband wrote, and thus “and he shall write for her a bill of severance” is fulfilled.
However, there are opinions that the husband is not required to write, and then the scribe does not need to be an agent at all. According to that view, the husband’s statement “write a get for my wife” only creates the requirement of writing it for her sake, and does not appoint an agent.
You, as an expert in the topic of “mere words,” surely know Rabbi Akiva Eiger, who wrote that according to the view that there is no agency in mere words—and not that it is only a problem in appointing a second agent—it is difficult how a husband can tell a scribe to write a get, since that is agency for mere words. And he answers as above: that this is not the appointment of an agent.