  While there is universal agreement that agents ought to act ethically, there
is no agreement as to what constitutes ethical behaviour. To address this
problem, recent philosophical approaches to `moral uncertainty' propose
aggregation of multiple ethical theories to guide agent behaviour. However, one
of the foundational proposals for aggregation - Maximising Expected
Choiceworthiness (MEC) - has been criticised as being vulnerable to fanaticism;
the problem of an ethical theory dominating agent behaviour despite low
credence (confidence) in said theory. Fanaticism thus undermines the
`democratic' motivation for accommodating multiple ethical perspectives. The
problem of fanaticism has not yet been mathematically defined. Representing
moral uncertainty as an instance of social welfare aggregation, this paper
contributes to the field of moral uncertainty by 1) formalising the problem of
fanaticism as a property of social welfare functionals and 2) providing
non-fanatical alternatives to MEC, i.e. Highest k-trimmed Mean and Highest
Median.
