Coherence and Conservatism in the Dynamics of Belief
  PartI: Finding the right framework
Hans Rott

In this paper I discuss the foundations of a formal theory of coherent and 
conservative belief change that is (a) suitable to be used as a method for 
constructing iterated changes of belief, (b) sensitive to the history of 
earlier belief changes, and (c) independent of any form of dispositional
coherence. I review various ways to conceive the relationship between the
beliefs actually held by an agent and her belief change strategies (that also 
deal with potential belief sets), show the problems they suffer from, and 
suggest that belief states should be represented by unary revision functions 
that take sequences of inputs. Three concepts of coherence implicit in 
current theories of belief change are distinguished: synchronic, diachronic 
and dispositional coherence. Diachronic coherence is essentially identified
with what is known as conservatism in epistemology. The present paper 
elaborates on the philosophical motivation of the general framework; formal 
details and results are provided in a companion paper.