You and I and all of this on this forum rely heavily on the rules of logic. The internet would not be possible without the rules of logic.
Circular definitions are not logically valid.
Yes, but to say that they are not allowed is a subjective norm. And further you run nito the problem if it is possible to do a human life as such for all of a human life following the rules of logic. Not that logic works in some cases, but that it works in all.
So for your rule to be objective you must show that it is possible to follow the rules of logic for all of a human life. Otherwise it is a free floating subjective norm without evidence.
You must remember that this is over 2000 years old for the attempt to do what you want to make a rule. And in fact nobody has so far been able to do that in all of recorded history.
So that you claim an universal fact, namely that the rules of logic govern all of human life only matter if it is possible to do so for morality in the end. And that connects to truth, knowledge and logic, and not just logic.
So try more than you just saying it is so. Show that it is so.
And that is philosophy in the end. It is not science, but the oldest form of knowledge we have and that is not that easy to do, because a lot of people can't catch when they are subjective and not objectively rational and with objective truth.