The Commens Dictionary
Quote from ‘Materials for Monist Article: The Consequences of Pragmaticism. Vols. I and II [R]’
Doubt is a state of mind characterized by a feeling of uneasiness. Nevertheless, we cannot from a logical, and especially from a pragmaticistical point of view, regard the doubt as consisting in feeling. [—] A true doubt is […] a doubt which really interferes with the proper action of a belief-habit.