  Conversely, one crucial premise in the regress argument claims that no moral belief can be justified non-inferentially. Another crucial premise, (8), claims that an inference cannot justify its conclusion unless its premises are justified. These premises claim, in effect, that a moral belief needs a certain kind of justification. One way to establish this need is to point to a contrary possibility that is not yet ruled out. That is what the skeptical hypothesis argument does. Another way to confirm this need is to show that the moral belief is controversial. That is what the argument from moral disagreement does. Thus, if these other arguments work, they support a crucial premise in the regress argument.