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Ideas for 'Mahaprajnaparamitashastra', 'Begriffsschrift' and 'poems'

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5 ideas

5. Theory of Logic / G. Quantification / 1. Quantification
A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman]
     Full Idea: The contribution of the quantifier to the truth conditions of sentences of which it is a part cannot be adequately explained if it is treated as other than a second-level predicate (for instance, if it is viewed as name).
     From: report of Gottlob Frege (Begriffsschrift [1879]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2
     A reaction: They suggest that this makes it something like a 'property of properties'. With this account it becomes plausible to think of numbers as quantifiers (since they do, after all, specify quantities).
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
For Frege the variable ranges over all objects [Frege, by Tait]
     Full Idea: For Frege the variable ranges over all objects.
     From: report of Gottlob Frege (Begriffsschrift [1879]) by William W. Tait - Frege versus Cantor and Dedekind XII
     A reaction: The point is that Frege had not yet seen the necessity to define the domain of quantification, and this leads him into various difficulties.
Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege]
     Full Idea: For Frege there is no need to specify the domain of the individual variables, which is taken as the totality of all objects. This contrasts with the standard notion of an interpretation, which demands that we first fix the domain.
     From: comment on Gottlob Frege (Begriffsschrift [1879]) by Michael Dummett - Frege Philosophy of Language (2nd ed) Ch.14
     A reaction: What intrigues me is how domains of quantification shift according to context in ordinary usage, even in mid-sentence. I ought to go through every idea in this database, specifying its domain of quantification. Any volunteers?
5. Theory of Logic / G. Quantification / 3. Objectual Quantification
Frege introduced quantifiers for generality [Frege, by Weiner]
     Full Idea: In order to express generality, Frege introduced quantifier notation.
     From: report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege
     A reaction: This is the birth of predicate logic, beloved of analytical philosophers (but of no apparent interest to phenomenalists, deconstructionists, existentialists?). Generality is what you get from induction (which is, of course, problematic).
Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh]
     Full Idea: Frege treated 'everything' as basic, and suggested ways of recasting propositions containing other quantifiers so that this was the only one remaining. He recast 'something' as 'at least one thing', and defined this in terms of 'everything' and 'not'.
     From: report of Gottlob Frege (Begriffsschrift [1879]) by Gregory McCullogh - The Game of the Name 1.6
     A reaction: Extreme parsimony seems highly desirable in logic as well as ontology, but it can lead to frustrations, especially over the crucial question of the existence of things quantified over. See Idea 6068.