I largely agree with the post. Saying Robertson's thought experiment was off limits and he was fantasising about beheading and raping atheists is silly. I think many people's reaction was explained by their being frustrated with his faulty assumption that all atheists are necessarily (implicitly or explicitly) nihilists of the sort who'd say there's nothing wrong with murder.
One amendment I'd make to the post is that many error theorists and non-cognitivists wouldn't be on board with what the murderer is saying in the thought experiment. For example, they could be quasi-realists. I say this as someone who personally leans moral realist.
He's not fantasizing about he himself beheading atheists. What he's fantasizing about is subtly different: he's fantasizing about the idea that atheists will get beheaded because of their own atheism rebounding on them, so it's their own fault.
Link to Blog Post: "Extremism in Thought Experiments is No Vice"
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This is a LW discussion post for Yvain's blog posts at Slate Star Codex, as per tog's suggestion:
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