  An extended analysis is given of the program, originally suggested by
Deutsch, of solving the probability problem in the Everett interpretation by
means of decision theory. Deutsch's own proof is discussed, and alternatives
are presented which are based upon different decision theories and upon
Gleason's Theorem. It is argued that decision theory gives Everettians most or
all of what they need from `probability'. Some consequences of (Everettian)
quantum mechanics for decision theory itself are also discussed.
