Teorias de Mudança de Crenças (Dinâmica Doxástica) - IFCS

Can we reduce the dynamic case (D) to the static one (S)?
3. (K, K ′ ) is D-justified iff K ′ is better S-justified than K.
Justificação epistêmica
• (→) Good transition to bad beliefs: The transition could be a D-good one – required
under the circumstances – without K ′ being S-better than K.
· K ′ result from K by adding some contingent information. Some such additions
must be D-justfiable so let us assume that (K, K ′ ) is. But K ′ is riskier than K.
Thus, if we assume that the degree of S-justification decreases as the risk of error
increases, then K ′ is less S-justified than K.
• (←) Bad transition to better beliefs: K ′ could be S-better than K but there is no
way of getting from K to K ′ in a D-justified manner.
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· Let A ∈ K be a well-(S-)justified belief. Let K ′ contain only those beliefs that are
at least as S-justified as A. The K ′ is certainly S-better than K. But the transition
(K, K ′ ) involves a gratuitous loss of information and is therefore not D-justified.