Why Coherence Matters

Explicating the concept of coherence and establishing a measure for assessing the coherence of an information set are two of the most important tasks of coherentist epistemology. To this end, several principles have been proposed to guide the specification of a measure of coherence. We depart from this prevailing path by challenging two well-established and prima facie plausible principles: Agreement and Dependence. Instead, we propose a new probabilistic measure of coherence that combines basic intuitions of both principles, but without strictly satisfying either of them. It is then shown that the new measure outperforms alternative measures in terms of its truth-tracking properties. We consider this feature to be central and argue that coherence matters because it is likely to be our best available guide to truth, at least when more direct evidence is unavailable