Abstract
Bias is a failure of critical doubt to function correctly in argumentation in a given context of dialogue. Critical doubt, in turn, is a kind of attitude one participant has toward the attitude of another participant in dialogue. Bias is associated with failure to be open to new or contrary evidence that comes into a critical discussion. Bias is also shown to be associated with certain kinds of failures of good argumentation associated with several of the traditional informal fallacies. After examining the role of the concept of critical doubt in defining bias, the article concludes by offering a provisional definition of bias that brings together what appear to be the most valuable and useful of the various hypotheses and proposed characteristics arising from the discussion.