Thank you, Rabbi, for the answer. I started reading the third part of the fourth notebook.
The Rabbi said that the good and the proper are the sought thing itself. What is good? What is proper? Do they have an objective definition? As I understand it, their definition changes according to whoever defines them.
According to this, there is God, but there is no objective morality. Because God says what is moral according to His will, but I have no desire to be godly or perfect or to walk in God’s ways, so why should anything He says obligate me?
Again, many thanks to the Rabbi. I hope I’m not wasting his time for nothing. I really want to understand.

Hello. You’re mixing together different levels of discussion. The fact that there is disagreement does not mean that morality is relative. It only means that there are different opinions about it. It is still possible that one is right and the other is wrong. In Jewish law too there are many disputes (far more than in morality), and the assumption is still that there is correct and incorrect Jewish law, and that someone can be mistaken or correct in Jewish law. Beyond that, contrary to your assumption, disagreements in the area of morality are relatively marginal. The overwhelming majority is completely agreed upon.
True, because of the differences of opinion, and because everyone has his own view, it is clear that the way I decide what the correct morality is—the one that the Holy One, blessed be He, expects of me—is by deciding what I think is moral and what is not. And indeed, such decisions can come out differently for different people. And still, in my opinion one is right and the other is wrong, and even if we did not succeed in convincing one another, that does not mean that we are both right. Therefore, from my perspective, if my conclusion is that act X is moral, then from my perspective that is the will of God, and I am obligated to do it.

Hello Rabbi, and thank you.
The claim is not that there is disagreement and therefore there is no moral truth, but that from the very definition of morality as seeking the good, it follows that there is no objective definition but only a subjective one, because each person will define the good according to his own desire. Or in other words, there is no truth in desire. No desire is more correct or less correct.
I’d be glad to understand how one sees that there is in fact a truer desire, or how the definition of morality implies that it is not subjective.
Again, thank you very much, Rabbi.

That does not follow from the definition of morality. It is a claim that I think is true because that is how I feel. That’s all.
Your claim against this is incorrect, because you assume that the good comes to achieve goals, and since each person has different goals, the good is therefore different. But that is a mistake, because the good is itself the goal, and it serves no other goal besides itself. This has nothing to do with a person’s desire. One person desires the good and another does not, but desire does not define the good. See the beginning of my remarks in the fourth notebook, part three, against the words of Ari Elon.

Hello again, Rabbi. And thank you for your time.
A. So what does define the good besides me?
B. What I found in the third notebook regarding Ari Elon is: “If so, the sovereign picture that Ari Elon paints is partial and inaccurate. A person cannot establish values for himself. He chooses how to live and to which values to be committed, but he is not the one who determines which values are the correct ones. Therefore our evaluation of that person’s path and personality also depends on some standard that exists outside of him (which determines whether his values are correct or not) and not only on the criterion of sovereignty. One may say that Elon’s basic mistake is in identifying morality with autonomy. The autonomy of the agent is a necessary but not sufficient condition for his morality, and it is certainly not correct to identify the two.”
I did not find any other proof, only the statement that it is obvious that a person cannot determine morality for himself.
If the Rabbi can explain the logic of this. (If the Rabbi answers that this is not morality, I’d be glad to hear a definition of what morality is.)

I have no proof other than the fact that each of us intuitively understands that morality obligates. As I explained there, the conception that morality obligates is grounded in God, in objective morality. You can of course assume the opposite, but then according to your view there is no morality (at most there is autonomy). To speak about morality while assuming that it is not objective is simply a conceptual confusion.

Thank you, Rabbi! Later on in the third notebook (around 81–87), regarding aesthetic claims and the like, I saw that the Rabbi presents exactly the argument I had heard. I managed to understand why this is not a proof, but rather is built on an axiom that morality is the result of inward introspection, and the Rabbi explained that the soul is only a tool for contemplating the idea of the good. And all this is for someone to whom it seems that morality obligates both himself and others. If I have more difficulties, I’ll keep writing. Thank you, Rabbi.

With pleasure