Can you be 100% confident in your moral beliefs?

The clarification makes sense. As I wrote above, I should have thought of murder being defined this way. 

Well, I'm pretty sure that "1 + 1 = 2" but couldn't I be convinced otherwise? In that case, is it still reasonable to say that I am 100% confident that "1 + 1 = 2"? I feel like this is exactly what I am trying to ask here. 

Can you be 100% confident in your moral beliefs?

Yes, ethics often deals with stuff that is not clear cut and obvious. 

I guess my conception of confidences might be flawed, do you have any recommended reading or some video clearing up what confidences are exactly? It seems that a lot of disagreements boil down to using some term in a different way, right? Isn't this what Yudkowsky wrote about?

Can you be 100% confident in your moral beliefs?

Thank you for the answer! I thought the Goodheart effect was about metrics turning bad when they become the thing you are optimising for. Does the term apply to something else here? 

The term "murder" refering to something immoral by definition makes sense, I should have thought about this more explicitely. 

Your advice in the last paragraph resonates with me. My experience has also been that people often seem to prioritize signaling. I am not a big fan of Jordan Peterson, but this reminded me of a quote of his: "If you can't understand why someone is doing something, look at the consequences of their actions, whatever they might be, and then infer the motivations from their consequences."