Tricky to do without giving you an archive link of a post with his last name on it, which I'm disinclined to do. Here, in this community, with this community's norms, I'm happy to oblige him. But here is not the real world.
Come on; Scott Alexander Siskind now has his real name published in New York Times, RationalWiki, and Wikipedia, since early 2021. You can find this all on the first page of Google results (exactly as he predicted). He even mentioned his name in the first article on his Substack blog, but then returned to the pen name his readers are more familiar with.
And he has already lost the job he was trying to protect back then. Now AFAIK his main source of income are subscriptions on Substack, and obviously those are not threatened in any way by having his name mentioned one more time.
Please let's respect each other's intelligence by not playing the game of pretending that posting Scott's full name before 2021 is the same as posting Scott's full name after 2021.
So, do you have examples of "some of his best-known posts published under his own name" before 2021?
He had a blog before Slate Star Codex. The impression I have is that I know more about this than you, and I'm not invested in this discussion enough to educate you adversarially, so I think it makes the most sense to just leave this subthread where it lies.
