Why? After all, the Rabbi uses this kind of argument with respect to categories like good and beauty, and even free choice.

I don’t remember using it.

In Quartet and in The Sciences of Freedom (there at least as an option). In any case, why does it seem weak to you?

If you want to discuss it, present a formulation of it here and we can discuss it. Different people call different arguments by that label.

The concept of meaning expresses an external purpose imposed on a person, and therefore when a person recognizes the meaning of this concept, he cannot arrive at it from within himself or from social convention, since by definition it stands as an autonomous and independent object.

And therefore?

Are you talking about the concept of meaning itself, or about the particular meaning that you find for yourself?

It may be that your point of view regarding the particular meaning that you find for yourself is partial and limited, but that does not negate the very existence of this idea and its reality, which follows from the fact that its conceptual existence must stem from an external source, and therefore one can say that a person has a purpose/meaning.

You didn’t address my question. This vague formulation added nothing to the discussion.
You can argue that from the very fact that people find different meanings, it follows that there is some meaning. That deals with the concept of meaning as such (the existence of the concept of meaning says that there is meaning, otherwise where was it drawn from). And you can argue that if so-and-so thinks the meaning of his life is X, that means this is probably its meaning too (otherwise where did he draw it from).
Either way, the argument is weak because it assumes that a person cannot derive an unfamiliar concept except from cognition, and that this indicates objective existence. But a person can also imagine, and illusory feelings of meaning can arise within him, etc. Fear at night in the desert does not prove that there are demons there.
From an evolutionary standpoint, one can also argue that the concept of meaning arose because it has adaptive and survival value. Those in whom it existed survived.
What you can argue, however, is that if a person truly believes in meaning, then he assumes that it is not something created within him, but that it has an objective root. See Column 159 on meaning. That is a “theological” or “revealing” argument.

But as we learned, Rabbi, every act of imagination is preceded by some cognitive foundation, even if it expands and goes beyond reality in a person, and therefore if the core of the concept of meaning lies in its being autonomous and external, then its basic foundation is not invented, since this is a basic concept that cannot be based on an extension of another concept. Evolution too does not provide an explanation except for something that has some chance of existing in the first place, but the claim of the anthropological argument is that without an external foundation it cannot develop at all.

The evolutionary engine is mutations. There is no real limitation on what can arise there. And even defining from what point this is no longer an extension is an amazingly flexible matter. I asked about the demons at night.

Given that we agree that basic concepts must be a product of cognition, and evolution can only shape perceptions on top of them—an extension of which basic concepts could fit the concept of meaning (in the sense of some meaning, not subjective meaning)?

I don’t see the point of this discussion. A person finds within himself a feeling of meaning even though it was created merely as an evolutionary mutation. What exactly is there to explain here?