摘要: The idea that belief comes in degrees is based on the observation we are more certain of some things than others. Various theories try to give accounts how measures this confidence do or ought behave, both as far internal mental consistency agent well his betting, other, behaviour concerned. This anthology first book a balanced overview these theories. It also explicitly relates debates traditional concerns philosophy language and mind, epistemic logic, namely simpliciter does behave. paradigmatic theory, probabilism (which holds satisfy axioms probability theory) given most attention, but competing theories, such Dempster-Shafer possibility AGM revision theory considered. Each approaches represented by one its major proponents. papers specifically written target advanced undergraduate students with background formal methods beginning graduate students, they will serve point reference for academics new area.