  Although the possibility of these alternative explanations does not establish that moral knowledge is possible, anyone arguing to the opposite conclusion by inference to the best explanation needs to make a plausible case that they can all be eliminated. Moreover, as defenders of moral knowledge point out, unless such a case is made out, the default position should be that we know some moral truths. Defenders note that moral language is formulated as if moral claims can be true and that we worry about whether to believe certain moral claims just as if truth is at stake. When challenged we appeal to evidence just as we do in the instance of straightforwardly factual claims, and we make logical inferences that conform to logical systems based on claims having truth-values. Though these points are not decisive, they underline the importance of eliminating alternative explanations of moral disagreement before concluding that moral knowledge is impossible.