|Boer, Steven E.
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Attribution of believe/Boer: known problem: that the logical equivalence fails here.
Problem: if the words in P are replaced by others.
Notation/Terminology/Boer: "≡" is the truth-functional analog of "if and only if" (iff).
"Bel (A, p)": "A believes that p".
Attribution of believe/Intentionality/Boer: Question:
A) is believe intentional?
B) is attribution of believe intentional?
Quine/Boer: his semantic rise has caused the second question to conceal the first.
Definition Intensionality/(sic, with s)/Boer: is nowadays negative, defined as non-intensionality.
So we need a definition of "extensional sentence".
Denotation/denoting/Boer: Assuming, denotating terms are: names, indices, demonstrativa and mass terms.
Definition English +/Boer: be an extension of English by zero or more denotating expressions and predicates.
Definition extensional reading/Boer: (provisional): E.g.: "A thing x is such that ... x ..." is unambiguous, then it is an extensional reading S iff it fulfills the following extensional principles:
Definition: a strong principle of existential generalization/extensibility/Boer: for a denotating term D and variable v which does not belong to S if S has the form [... D ...], then one can conclude from S validly [an existing thing v is such that ... v ...].
Definition: replacement princinple for co-extensive predicates/Boer: ... from [for objects x1, ... xn, either P (x1, ... xn) or Q(x1, ... xn) or neither P nor Q] we can exclude any theorem which is obtained by replacing one or more occurrences of P in S by Q.
Definition replacement princinple for materialistic equivalent sentences/Boer: for every sentence P and Q in English +, if P is present in S, one can deduce from S and [Either P and Q, or neither P nor Q] every sentence which is formed by the replacement of one or several occurrences of P in S by Q.
Definition of the substitutionality of the identity/Boer: for each denotating term D and E of English +: if S has the form [... D ...], one can deduce from S and an equation of the form [D = E] (or [E = D] every sentence which is formed by replacing one or more occurrences of D by E in S.
Validity/everyday language/Boer: can only be asserted relatively to a particular reading.
English +/Boer: we need that to exclude the fact that the four principles are not trivially fulfilled by there being no counterexamples to the inferences in question simply because there are not enough names or predicates to formulate one.
Steven E. Boer
Thought-Contents: On the Ontology of Belief and the Semantics of Belief Attribution (Philosophical Studies Series) New York 2010
Steven E. Boer
Knowing Who Cambridge 1986