An Inconsistency in Craig's Defence of the Moral Argument

Wielenberg's article identifies a fundamental inconsistency in William Lane Craig's defense of the moral argument for God's existence. The moral argument, a cornerstone of Craig's natural theology, claims that objective moral values and duties cannot exist without God, yet clearly do exist, therefore God exists. Wielenberg demonstrates that Craig's responses to different objections against this argument contradict each other in a philosophically significant way.

The inconsistency concerns Craig's treatment of moral supervenience and the relationship between natural and moral properties. When defending against one type of objection, Craig endorses a strong supervenience thesis, maintaining that moral properties necessarily supervene on natural properties—that is, there can be no difference in moral properties without a difference in natural properties. However, when addressing a different challenge to the moral argument, Craig explicitly denies this same supervenience relationship, arguing that natural properties alone cannot determine moral properties without God's creative activity.

Wielenberg carefully traces this contradiction through Craig's various writings and debates. He shows that Craig invokes supervenience when responding to objections about God's moral nature and the Euthyphro dilemma, using it to explain how God's commands relate to objective morality. Yet Craig abandons this position when confronting naturalistic theories of ethics that might ground objective morality without God. This strategic shifting between incompatible positions, Wielenberg argues, undermines the coherence of Craig's moral argument.

The article's significance extends beyond exposing a mere technical inconsistency. Wielenberg demonstrates that this contradiction reveals deeper problems with divine command theories and theistic metaethics more broadly. If moral properties must supervene on natural properties, then Craig cannot simultaneously claim that God is necessary for grounding these supervening relations. If they need not supervene, then Craig loses his defense against arbitrariness objections to divine command theory.

Wielenberg's analysis employs careful philosophical argumentation, drawing on contemporary metaethical theory while engaging directly with Craig's published works and recorded debates. The article contributes to ongoing debates about moral realism, divine command theory, and the viability of moral arguments for theism. By revealing this internal tension in one of contemporary theism's most prominent arguments, Wielenberg challenges defenders of the moral argument to develop more consistent theoretical foundations or abandon certain defensive strategies that generate contradictions.