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Single Idea 11008

[filed under theme 7. Existence / A. Nature of Existence / 1. Nature of Existence ]

Full Idea

When Kant said that existence was not a property, what he meant was, according to Frege, that existence is not a first-order property - it is not a property of individuals but a property of properties, that the property has an instance.

Gist of Idea

Existence is not a first-order property, but the instantiation of a property

Source

report of Gottlob Frege (Begriffsschrift [1879]) by Stephen Read - Thinking About Logic Ch.5

Book Ref

Read,Stephen: 'Thinking About Logic' [OUP 1995], p.126

The 20 ideas from 'Begriffsschrift'

7622 In 1879 Frege developed second order logic [Frege, by Putnam]
7729 Frege replaced Aristotle's subject/predicate form with function/argument form [Frege, by Weiner]
9991 For Frege the variable ranges over all objects [Frege, by Tait]
10536 Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege]
9950 A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman]
13609 Frege produced axioms for logic, though that does not now seem the natural basis for logic [Frege, by Kaplan]
7730 Frege introduced quantifiers for generality [Frege, by Weiner]
7742 Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh]
13824 Proof theory began with Frege's definition of derivability [Frege, by Prawitz]
17855 It may be possible to define induction in terms of the ancestral relation [Frege, by Wright,C]
10607 Frege's logic has a hierarchy of object, property, property-of-property etc. [Frege, by Smith,P]
11008 Existence is not a first-order property, but the instantiation of a property [Frege, by Read]
22280 Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter]
7741 The predicate 'exists' is actually a natural language expression for a quantifier [Frege, by Weiner]
22270 Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege]
8939 We should not describe human laws of thought, but how to correctly track truth [Frege, by Fisher]
17745 For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki]
7728 Frege has a judgement stroke (vertical, asserting or judging) and a content stroke (horizontal, expressing) [Frege, by Weiner]
4971 I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege]
16881 The laws of logic are boundless, so we want the few whose power contains the others [Frege]