  The focus below is on arguments which seek to cast doubt on the existence of moral knowledge, even granted that there are moral truths. An alternative approach is to first argue that the disagreement directly excludes the existence of moral truths and then to simply derive the thesis that there is no moral knowledge from that conclusion (given that knowledge presupposes truth). That alternative strategy will be set aside in this section. Thus, since the arguments are supposed to support skeptical conclusions independently of any rejection of moral truths, they need to establish that our moral beliefs violate some other precondition of knowledge, such as, most commonly, justification.