Apparently,this sentence states a comparison between a nauseated person (NP)and a murdered one (MP), that is, the proposition: 'Just as a MP is not murderous, so a NP is not nauseous'. This interpretation treats the sentence as an strict expression of a propostion. But, the expression, 'A is no more x than B is', emphasises that A is not x at all.
Thanks so much! I got it now. I think the tricky point here is " a person who has been murdered is murderous." How can a murdered person BEING MURDEROUS! Makes no sense at all....