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Single Idea 18801

[filed under theme 5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not ]

Full Idea

Explanations of classical negation assume that knowing what it is for the truth-condition of some statement to obtain, independently of recognising it to obtain, we thereby know what it is for it NOT to obtain; but this presupposes classical negation.

Gist of Idea

Classical negation is circular, if it relies on knowing negation-conditions from truth-conditions

Source

Michael Dummett (The Logical Basis of Metaphysics [1991], p.299), quoted by Ian Rumfitt - The Boundary Stones of Thought 1.1

Book Ref

Rumfitt,Ian: 'The Boundary Stones of Thought' [OUP 2015], p.4


A Reaction

[compressed wording] This is Dummett explaining why he prefers intuitionistic logic, with its doubts about double negation.

Related Idea

Idea 18799 Intuitionists can accept Double Negation Elimination for decidable propositions [Rumfitt]


The 13 ideas with the same theme [role of 'not' in systems of logic]:

The contradictory of a contradictory is an affirmation [Stoic school, by Diog. Laertius]
Normativity needs the possibility of negation, in affirmation and denial [Fichte, by Pinkard]
Negation of negation doubles back into a self-relationship [Hegel, by Houlgate]
Is it possible to state every possible truth about the whole course of nature without using 'not'? [Russell]
Negations are not just reversals of truth-value, since that can happen without negation [Wittgenstein on Russell]
We may correctly use 'not' without making the rule explicit [Wittgenstein]
'Not' isn't an object, because not-not-p would then differ from p [Wittgenstein]
Negation doesn't arise from reasoning, but from deep instincts [Cioran]
Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen]
Classical negation is circular, if it relies on knowing negation-conditions from truth-conditions [Dummett]
Natural language 'not' doesn't apply to sentences [Dummett]
'A is F' may not be positive ('is dead'), and 'A is not-F' may not be negative ('is not blind') [MacBride]
Standard logic only negates sentences, even via negated general terms or predicates [Engelbretsen]