Disagreement-based uncertainty for decision making

Abstract Given the importance that it has in almost any decision, understanding uncertainty and its possible variations is crucial in deciding effectively. I propose an account of uncertainty as based on a disagreement between reasons for and against alternative mental attitudes. Under this account, dealing with uncertainty means dealing with disagreement; however, this disagreement can be radical, i.e., persistent under ideal cognitive and epistemic conditions. Thus, when this is the case, the disagreement and therefore the uncertainty cannot be resolved with an increase in evidence. I illustrate how this unitary notion can be used to derive different types of uncertainty proposing a possible typology that reflects the conditions that must obtain for radical disagreement, and I trace the role that each of the types identified plays in decision making. This application to decision making suggests that there are uncertainties that go beyond those modelled in mainstream decision theory.