Mixed Political Inferences

The relation between logic and ethics is discussed through the reflections proposed by Corcoran. Although the latter claimed the inseparability of both normative disciplines and their reciprocal virtues, a number of arguments have been advanced for their complete separation by rejecting the alleged validity of mixed inferences, i.e., those inferences including both descriptive and non-descriptive statements. After examining the import of logic into the area of ethics, an isomorphism argument is advocated to validate logical inferences between moral statements. Then such inference rules are introduced into political discourse as a special kind of moral statements, including the famous left–right cleavage and the formal analysis of such an opposition in terms of moral commitments.