> Would you mind explaining?

Alright. They pointed to how you used the concept of "of the opinion". This is the phrase that you have used yourself in the previous comment.

Even if the conversation wasn't about free will, that phrase would indicate something meaningful about your thought process, which is why you used it. Also we all, who read your comment had no trouble interpreting your phrase, and neither why you used it that way, what exactly you meant, and why it was meaningful to use it in that way.

Now, the poster who answered to you, pointed to that exact phrase, to ironically show to you that while you (one part of your mind) is sitting here and trying pretend that free will is a meaningless thing (~ to talk about), another part of your mind, uses the very concept of free will, to communicate to us about the first part. To make it clear: you saying "I am of the opinion of..." already implies that you assume that you have free will, to have opinions.

Now, as I am sure you are already preparing to congest about this point, there are many various definitions of free will, where some of them will be used in the concept of "I am of the opinion", and some of them will not be related to it, it is safe to say that there is at least a number of them that are usefully related to your claim.

The ones that are related go something like that: "if you truly had no free will, if you are a simple list of if/thens, or a dumb version of GPT-3, then why would we care that you had this opinion? rulesets cannot have opinions. If you did not have free will, there is no point in talking to you, your "opinion" doesn't matter, it's a meaningless term. But since we choose (consciously or subconsciously) to communicate with you, to discuss your "opinion", it means that we are taking a chance that you do have free will so that we can communicate with you".

Now, that line of reasoning - it's not 100% ironclad, there are presuppositions and assumptions, and this is partly what I meant when I said "coherence of the concept of free will is icky", but I think it is safe to say that you could at least follow it. To do that, you had to use the concept of free will, at least subconsciously, because the concept of "I am of the opinion" is based on it in some form. And since you used that phrase from the beginning, it is already assumed to be useful to you. (Why would you use it otherwise? Do you just type words into ether for no reason?)

It is not the best or most useful explanation of the usefulness of the term free will in general, but it is one of the best that I can see that can directly relate to the funny thing that happened between you and that poster, which you didn't seem to get. Hopefully, if you get the humor, that will tell you much more about the deeper intuitions about the term "free will", than what the logical overthinking about it can.

I am not saying that we can't understand free will with logic. I am saying that in this specific case, the interesting point was the irony and the intuitive connection, instead of logical explanations.

> Perhaps so but the existence of day-to-day commonplace irrationality is no justification for importing irrational specters into philosophy.

How do you equate "usefulness" with "irrationality"?

I said there are useful, meaningful (well-seving as tools of thinking and awareness-ing) concepts that don't have coherent, well-defined borders or black-and-white definitions. That is not the same as them being irrational. A lot of concepts can't be put in very limited contraints of a-b-c logic. And yet we have other faculties that allow us to reason about these concepts. Meaning, we use those concepts because they help us understand the world and pursue our goals.