ABSTRACT
Reason is imperfect – there is a permanent possibility of error. Knowledge is achieved through the elimination of doubt, and what eliminates doubt is the existence of a compelling reason. But doubt is more infectious than it first appears, for one might doubt whether one’s reason really is compelling, doubt whether the reason for thinking that it is compelling is itself compelling, and so on forever along a familiar evidential regress. Doubts cascade, and truly compelling reasons are scarce. Even when they are to hand, their value is limited – for not even psychological certainty can exclude the logical possibility of error. So it transpires that the hard question is not how to free one’s inner space from all doubt (an impossible project of dubious value), but how to live with the uncertainty with which it is necessarily infused.
