Modelling the Moral Dimension of Decisions: Modelling the Moral Dimension of Decisions

Abstract

Standard decision theory is often assumed to carry an inherent bias toward consequentialism due to its maximization of expected utility over act outcomes. However, non-consequentialist frameworks—specifically deontology and virtue ethics—can be formally accommodated within standard von Neumann–Morgenstern expected utility theory through systematic constraints on utility functions. Utilitarianism maps directly by indexing utility to cardinal measures of welfare. Deontological constraints can be represented by individuating outcomes with respect to the actions that produce them and assigning finite, hierarchically differentiated utilities to duties; however, accommodating defeasible duties and mixed acts reveals tensions with core axioms like continuity. Virtue ethics can be incorporated by discriminating acts based on their underlying motivations and applying additive utility factors to reflect virtuous or vicious agency. While these formal adaptations demonstrate that standard decision theory is not exclusively consequentialist, the resulting models function descriptively rather than explanatorily. They reproduce the correct action choices of non-consequentialist agents while failing to represent the internal motivations, moral psychology, and normative justifications that fundamentally ground deontological and virtue-theoretic traditions. Consequently, standard decision theory is not ethically neutral, as fitting non-consequentialist ethics into its framework distorts their foundational principles. – AI-generated abstract.