Might be worth addressing Pinker's arguments even if it's unlikely to get him to change his mind. He's an influential guy (Hanania also has a relatively large platform), so it could help to persuade their audience

How would you interpret the zombie argument so that it’s circular? Can you lay it out explicitly like above?

Let's suppose that the zombie argument smuggles in the assumption that what you're imagining is evidence of reality. Then the argument would look like this:

1. I can imagine zombies as possible.
2. My imagination is evidence of reality.
3. So I have evidence that zombies are possible.
4. The possibility of zombies is inconsistent with physicalism.
5. Therefore, I have evidence physicalism is false.

This still isn't a circular argument. It's just an argument with a false premise, namely premise 2.

More generally, if you think an argument lacks support, that doesn't mean it's circular.

Here's another parody argument:

It seems to me that birds are possible. So any theory that claims that mammals are the only animals (and hence that birds are impossible) is false.

Is this argument circular? I assume not. But it seems to have the same structure as the zombie argument.

Here's a kind of parody that one might run:

It's the physicalist who's begging the question. The physicalist is saying zombies are impossible. But what's their reason for thinking zombies are impossible? To argue that zombies are impossible, they have to implicitly assume non-physicalism is wrong in order to conclude that it's wrong. Thus, it's circular reasoning.

I reject that either physicalist or non-physicalist is necessarily making a circular argument. They just have different intuitions about whether zombies are possible. You might in fact think that zombies are impossible but then that's the reason to reject the argument, not that it's circular.

You might not think that zombies are possible. But then that would be the problem with the argument. It's not that the argument is circular. It's that one of the premises is false (or unjustified).

It's true that a physicalist would say that zombies are impossible. But that's the point of the argument! It's showing how one of the implications of physicalism is false—zombies are possible.

You might have independent reasons for thinking that zombies are impossible. But the mere fact that the argument is premised on the possibility of zombies doesn't make it circular.

I think this post could be improved by including some quotations at the beginning that are representative of the dogmas of LessWrong. The Eliezer quotes are good, but I can't recall any explicit posts about moral anti-realism on LessWrong.

The popularity of TTS might be due to the fact that it’s relatively low cost to produce. But given that there’s already real-person audio narration of the sequences, it might be worth adding that in instead and seeing if that’s more engaging