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Single Idea 7741

[filed under theme 28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique ]

Full Idea

On Frege's logical analysis, the predicate 'exists' is actually a natural language expression for a quantifier.

Gist of Idea

The predicate 'exists' is actually a natural language expression for a quantifier

Source

report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege Ch.8

Book Ref

Weiner,Joan: 'Frege' [OUP 1999], p.133


A Reaction

However see Idea 6067, for McGinn's alternative view of quantifiers. In the normal conventions of predicate logic it may be that existence is treated as a quantifier, but that is not the same as saying that existence just IS a quantifier.

Related Idea

Idea 6067 Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn]


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]