Unity and Coherence in Explanatory Virtues

Abstract The systematization of evaluation criteria for scientific theories, also known as theoretical virtues, aims to enhance understanding and objectivity in theory evaluation, and thereby to facilitate consensus formation. Explanatory virtues play a crucial role here. They are well known individually, but lack a widely accepted organization, especially with regard to how simplicity integrates with the other explanatory virtues. This work introduces a unificatory model of virtues (UM), in which simplicity is integrated in a way that yields a concise hierarchical organization of the explanatory virtues. In UM, a theory’s accuracy, explanatory depth, internal consistency, and ontological simplicity are components of its unifying power, while its consistency and explanatory relations with other theories are components of both its external coherence and the unifying power of the set of theories under consideration. Arguably, UM is in some ways more advanced than the coherential virtue models of Michael Keas and Adolfas Mackonis, such as in providing a quantitative criterion for a theory’s fitness. UM and its comparison with the coherential models are valuable for anyone who seeks a deeper understanding of explanatory virtues.