Belief and Surprise - A Belief-Function Formulation
  We motivate and describe a theory of belief in this paper. This theory is
developed with the following view of human belief in mind. Consider the belief
that an event E will occur (or has occurred or is occurring). An agent either
entertains this belief or does not entertain this belief (i.e., there is no
"grade" in entertaining the belief). If the agent chooses to exercise "the will
to believe" and entertain this belief, he/she/it is entitled to a degree of
confidence c (1 > c > 0) in doing so. Adopting this view of human belief, we
conjecture that whenever an agent entertains the belief that E will occur with
c degree of confidence, the agent will be surprised (to the extent c) upon
realizing that E did not occur.
