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Single Idea 7730

[filed under theme 5. Theory of Logic / G. Quantification / 3. Objectual Quantification ]

Full Idea

In order to express generality, Frege introduced quantifier notation.

Gist of Idea

Frege introduced quantifiers for generality

Source

report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege

Book Ref

Weiner,Joan: 'Frege' [OUP 1999], p.44


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).


The 20 ideas from 'Begriffsschrift'

In 1879 Frege developed second order logic [Frege, by Putnam]
Frege replaced Aristotle's subject/predicate form with function/argument form [Frege, by Weiner]
For Frege the variable ranges over all objects [Frege, by Tait]
Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege]
A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman]
Frege produced axioms for logic, though that does not now seem the natural basis for logic [Frege, by Kaplan]
Frege introduced quantifiers for generality [Frege, by Weiner]
Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh]
Proof theory began with Frege's definition of derivability [Frege, by Prawitz]
It may be possible to define induction in terms of the ancestral relation [Frege, by Wright,C]
Frege's logic has a hierarchy of object, property, property-of-property etc. [Frege, by Smith,P]
Existence is not a first-order property, but the instantiation of a property [Frege, by Read]
Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter]
The predicate 'exists' is actually a natural language expression for a quantifier [Frege, by Weiner]
Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege]
We should not describe human laws of thought, but how to correctly track truth [Frege, by Fisher]
For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki]
Frege has a judgement stroke (vertical, asserting or judging) and a content stroke (horizontal, expressing) [Frege, by Weiner]
I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege]
The laws of logic are boundless, so we want the few whose power contains the others [Frege]