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Single Idea 13254

[filed under theme 4. Formal Logic / E. Nonclassical Logics / 5. Relevant Logic ]

Full Idea

We could reject the inference from A to itself (on grounds of circularity).

Gist of Idea

A doesn't imply A - that would be circular

Source

JC Beall / G Restall (Logical Pluralism [2006], 8)

Book Ref

Beall,J/Restall,G: 'Logical Pluralism' [OUP 2006], p.91


A Reaction

[Martin-Meyer System] 'It's raining today'. 'Are you implying that it is raining today?' 'No, I'm SAYING it's raining today'. Logicians don't seem to understand the word 'implication'. Logic should capture how we reason. Nice proposal.


The 23 ideas from 'Logical Pluralism'

Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall]
Propositions commit to content, and not to any way of spelling it out [Beall/Restall]
Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall]
The view of logic as knowing a body of truths looks out-of-date [Beall/Restall]
Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall]
Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall]
Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall]
Judgement is always predicating a property of a subject [Beall/Restall]
A sentence follows from others if they always model it [Beall/Restall]
The model theory of classical predicate logic is mathematics [Beall/Restall]
Excluded middle must be true for some situation, not for all situations [Beall/Restall]
It's 'relevantly' valid if all those situations make it true [Beall/Restall]
Relevant necessity is always true for some situation (not all situations) [Beall/Restall]
Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall]
Relevant logic does not abandon classical logic [Beall/Restall]
A truthmaker is an object which entails a sentence [Beall/Restall]
We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall]
(∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall]
Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall]
Some truths have true negations [Beall/Restall]
A doesn't imply A - that would be circular [Beall/Restall]
Relevant logic may reject transitivity [Beall/Restall]
There are several different consequence relations [Beall/Restall]