Hi again, Bernard
I think you are dealing with minuscule unevidenced possibilities, as I noticed you do some time ago. Keep them if you please. But you look to me like as an extreme "uncertaintist".
You are, of course, entitled to your view. However, your opinion of me has no relevance to the questions discussed here.
This is not a methodological thread, but it is obvious that the evidence available to any of us is sparse and equivocal. It follows that our individual prior opinions, what "makes sense" to each of us, will differ and loom large in our individual conclusions. Personalizing that global situation to any individual is unhelpful.
I already explained that: there was no need to identify the James in Gal 2:9 & 12 other than by his name, because that was done in Gal1:19.
But Paul did anyway. So what?
Forget about 1 Corinthians "brothers of the Lord": these brothers are not identified by number & name.
I am reluctant to forget half of what little evidence there is on point. These brothers are plural, which suffices to conclude that James is not the only one whom Paul ever called the brother of the Lord
That's a small step but a step all the same in reconstructing what he meant. It also helps in estimating (against) the chances of interpolation, not a lot, but some.
And next, in Galatians, first it is James, the brother of the Lord, then James as one of the pillars. That follows the rule of good writing.
What Paul wrote is good writing if there were two Jameses, and equally good writing if there were only one James. Good writing doesn't discriminate between one-James and two-James hypotheses.
If I would mention in a text, at first, "Reagan, a past US president", and then a few lines after, I mention "Reagan" again (only his last name), everybody (except maybe yourself) will know it is Reagan, the former US president.
Paul did not refer to James on either occasion by name alone. So the better analogy would be a text where you wrote "Reagan, a past US President" then a few lines after, "Reagan, a former governor of California."
Now, I happen to know that there was one man named Reagan who was both president and governor, and only one US President named Reagan. So yes, you may rely on a contemporary American like me knowing who is being discussed, and that he is one person you've mentioned twice.
You cannot assume, and perhaps don't much care, whether your good writing will be as effortlessly understood two thousand years from now, particularly not in a discussion prompted by the question of what a "US president" meant to you, yours being the only then-extant use of the phrase.
Finally, I am glad to read that you and Ben
had a productive conversation here.