Reply to Akiba on the probabilistic measure of coherence
Intuitively C(B1, ... , BN) measures the degree by which the beliefs are more likely to be true together than they would be if they were related neutrally, i.e. if the truth of one belief had no impact on the truth of any other. It is meant to spell out the frequently proffered characterization that coherent beliefs hang together. Akiba claims my formula is 'demonstrably inadequate indeed, inconsistent for a measure of coherence' (356) and expresses his general pessimism about the prospect of formulating a plausible probability measure of coherence. To dispel his pessimism I shall address below the three problems Akiba raises.