more from this thinker     |     more from this text


Single Idea 16344

[filed under theme 5. Theory of Logic / K. Features of Logics / 3. Soundness ]

Full Idea

Soundness seems to be a notion essentially involving truth. At least I do not know how to fully express the soundness of Peano arithmetic without invoking a truth predicate.

Gist of Idea

Soundness must involve truth; the soundness of PA certainly needs it

Source

Volker Halbach (Axiomatic Theories of Truth [2011], 22.1)

Book Ref

Halbach,Volker: 'Axiomatic Theories of Truth' [CUP 2011], p.323


A Reaction

I suppose you could use some alternative locution such as 'assertible' or 'cuddly'. Intuitionists seem a bit vague about the truth end of things.


The 12 ideas with the same theme [whether all formal deductions always lead to truth]:

If soundness can't be proved internally, 'reflection principles' can be added to assert soundness [Gödel, by Halbach/Leigh]
A proof theory is 'sound' if its valid inferences entail semantic validity [Enderton]
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
If everything that a theory proves is true, then it is 'sound' [Smith,P]
Soundness is true axioms and a truth-preserving proof system [Smith,P]
A theory is 'sound' iff every theorem is true (usually from true axioms and truth-preservation) [Smith,P]
'Weakly sound' if every theorem is a logical truth; 'sound' if every deduction is a semantic consequence [Shapiro]
Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman]
Soundness theorems are uninformative, because they rely on soundness in their proofs [McGee]
You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system [Halbach]
Normally we only endorse a theory if we believe it to be sound [Halbach]
Soundness must involve truth; the soundness of PA certainly needs it [Halbach]