  Several rules for social choice are examined from a unifying point of view
that looks at them as procedures for revising a system of degrees of belief in
accordance with certain specified logical constraints. Belief is here a social
attribute, its degrees being measured by the fraction of people who share a
given opinion. Different known rules and some new ones are obtained depending
on which particular constraints are assumed. These constraints allow to model
different notions of choiceness. In particular, we give a new method to deal
with approval-disapproval-preferential voting.
