Description and Disjunction: Re ections on an Argument of Thomas Forster

Rohan French, Lloyd Humberstone

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After some stage-setting in Section 1, Section 2 presents a proof oered
by Thomas Forster (in his book Reasoning About Theoretical Entities)
to show that procedure oered for eliminating denite descriptions from
a certain range of formulas always yields a description-free equivalent
for any given description-containing formula. (This equivalent amounts
to a formula in which the description in question has been given the
broadest possible scope.) In Section 3, we show that the inductive case of
disjunction in this proof (by induction on formula complexity) does not
go through as claimed, and that the result itself is not correct. In Section
4 we look at some similarities and contrasts between Forster's proposed
elimination procedure and one emerging more directly from one prominent
strand { the binary quantier approach { in the Russellian legacy. This
leads us, on a more positive note, to a few observations about a class
of truth-functions intimately connected with that range of contexts in
which the descriptive binary quantier is \scope-indierent" { the falsitypreservingfunctions { from which we pass, by way of conclusion, to a
corrective reformulation suggested by that discussion for the descriptionas-
terms treatment of Forster's discussion.
Original languageEnglish
Number of pages28
JournalSouth American Journal of Logic
Issue number1
Publication statusPublished - 2018

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