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Single Idea 16881

[filed under theme 5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic ]

Full Idea

Since in view of the boundless multitude of laws that can be enunciated we cannot list them all, we cannot achieve completeness except by searching out those that, by their power, contain all of them.

Gist of Idea

The laws of logic are boundless, so we want the few whose power contains the others

Source

Gottlob Frege (Begriffsschrift [1879], §13)

Book Ref

'From Frege to Gödel 1879-1931', ed/tr. Heijenoort,Jean van [Harvard 1967], p.29


A Reaction

He refers to these laws in the previous sentence as the 'core'. His talk of 'power' is music to my ears, since it implies a direction of explanation. Burge says the power is that of defining other concepts.


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]