Question

I correctly guessed that in your Talmud lessons on Pesachim 26a you would discuss the loop regarding “a yoke was placed on it”: if that makes it fit, then he wants it; if it makes it unfit, then he does not want it. And my guess was indeed correct. You wondered why they stop the loop at the point of disqualification. For now I will relate only to the words of Tosafot.
 
A few comments:
1. It seems to me that the solution to this loop requires us to define what his intention is and what the law is.
A. As for his intention, it is as follows: if it is fit, then he wants it, in order to increase “be fruitful and multiply”; and if it is unfit, then he does not want it. And although we learned from Rabbi Shimon Shkop that an act cannot be done conditionally in every such way, that is only with regard to an act, because that is the nature of an act. I cannot write you a letter conditionally. But desire, on the contrary, can be split and split and split. For example: today I want to finish the Talmud tonight, on condition that I will also manage to sleep well and get up at sunrise. So from the standpoint of intention it turns out that it is hanging in suspense, and neither of the two tracks is correct: it is impossible to say “he does not want it and it is fit,” and impossible to say “he wants it and it is unfit.”
 

1. Now we have to discuss it from the standpoint of the law, and let us preface with Rabbi Yosef Shalom Elyashiv’s question: how is this different from mixed species, where we say that he does not want their continued existence during the intermediate festival days, since this will render it forbidden to him? Why should we not say, as Tosafot does, that if it is fit then he wants the mixed species?

And it seems that the point is: in every matter, what is the law that we must apply? In the case of mixed species, the law is to prohibit the mixed species. This is the law’s role: to prohibit. The thing is permitted until a prohibition takes effect on it, and the law is the prohibition. By contrast, in the case of the red heifer, fitness is the law. The heifer is not fit unless a yoke was placed on it with the owner’s consent. And one cannot say: the heifer is not unfit unless a yoke was placed on it with the owner’s consent, because the fitness of the heifer is the law that says that with such a heifer we fulfill our obligation. That is unlike a prohibition, where permission is not itself a legal status; rather, the prohibition is the law, and this will be further clarified below in section 3.
Therefore, each time, along the track of the law, we say that it has no realization. The prohibition-law of mixed species is not realized, because there is no such track, since if it becomes forbidden he does not want their continued existence. By contrast, with the fitness of the heifer, the law we must operate with is the heifer’s fitness. A heifer is not fit unless a yoke was placed on it with the owner’s consent, and here there is no such track in which the owner does not want it and the heifer is fit.

1. What stands behind these assumptions is that law is not a reality, like someone who says: do not drink poisonous material, because then you will die; where death is a fact, and one escapes it by not eating or drinking it. [For if that were so, we would have to ask in the abstract: is the poison of death here or not? was a yoke placed on it or not? and the answer would be: it is doubtful.] Rather, the law is to prohibit or to validate this thing. That is the law, and that is how it exists: to prohibit or permit this thing. Therefore we discuss the prohibition or the validation—whether it has room to take effect—and each time we also try to determine what the law is: the prohibition or the permission, the validation or the disqualification. In the next question I will address Rabbi Shimon Shkop’s consistency principle. Meanwhile, I would be glad to hear your response.