That's exactly what he's addressing, utilitarians with messed up definitions of utility. Your head needs to be awfully far up your ass to come to the conclusion that slavery is good without questioning the principles that lead to that conclusion.
I'd like to read arguments on both sides for the economic effects of, say, slavery in America. Did America benefit? If so, over what timescales? Were there benefits in the short term but the ongoing divisions now hurt the economy more? And I can wonder about these things while still not thinking it was good.
Of course, some people in this thread are probably ready to laud Hitler's economic acumen, while ignoring his economic gains were due to public spending building a war machine and taking Jewish people's stuff.
You're not allowed to comment like this on HN.
HN is one of those places where, as frustrating as it might be, the rules of discourse encourage thoughtful interchange. Here, we at least have the hope that we can be educated or enlightened, and in some cases we may be able to show others the errors in their thinking in a manner that doesn't close off communication.
Most arguments I can come up with are reasonably close to contemporary arguments for socialism or basic income. Do you consider those arguments (far more socially acceptable) to be similarly "messed up"?
(Note that most of those who have advocated for slavery in recent years, e.g Obama and Rangell, did so from a socialist perspective. Slaves would serve the state, either as "volunteers" for social programs or in the military. I'm not the only one who finds the cases to be pretty close.)
I appreciate you supporting my case.