Xian He

This entry explains what the issue of weighing reasons is about and then discusses a number of theories concerning weighing reasons. The general issue concerns how reasons (or considerations or pros and cons) systematically interact to determine the normative status of some action, belief, or attitude. For example, it concerns how reasons determine whether an action is permissible, required, or what ought to be done. The general issue also concerns how reasons aggregate or themselves result from systematic interactions with the broader context. Along the way, the entry considers whether reasons can be incommensurable (e.g., be on a par); whether reasons have more than one weight value (e.g., justifying, requiring, and commending); the relation between reasons for and reasons against; conditions (enablers, disablers); modifiers (amplifiers, attenuators); exclusionary reasons; higher order evidence; what happens when, say, morality and epistemic rationality conflict; and so on.