Abstract What should we do when we discover that our assessment of probabilities is incoherent? I explore the hypothesis that there is a logic of incoherence?a set of universally valid rules that specify how incoherent probability assessments are to be repaired. I examine a pair of candidate?rules of incoherence logic that have been employed in philosophical reconstructions of scientific arguments. Despite their intuitive plausibility, both rules turn out to be invalid. There are presently no viable candidate?rules for an incoherence logic (...) on the table. Other ways of dealing with incoherence are surveyed, and found either to be unsatisfactory or to rely on a logic of incoherence in the end. The resolution of these antagonistic conclusions is left to future researchers. (shrink)

Rationality demands at least that we eliminate incoherencies among our beliefs when we are apprised of them. This minimal requirement gives us no grounds for condemning a refusal to look for incoherencies, or indeed to deliberate altogether. Several stronger conditions on rationality are explored and rejected. There are presently no good arguments against logical sloth.