  We propose a new model of incomplete preferences under uncertainty, which we
call unanimous dual-self preferences. Act f is considered more desirable than
act g when, and only when, both the evaluation of an optimistic self, computed
as the welfare level attained in a best-case scenario, and that of a
pessimistic self, computed as the welfare level attained in a worst-case
scenario, rank f above g. Our comparison criterion involves multiple priors, as
best and worst cases are determined among sets of probability distributions,
and is, generically, less conservative than Bewley preferences and twofold
multi-prior preferences, the two ambiguity models that are closest to ours
