more from this thinker     |     more from this text


Single Idea 19137

[filed under theme 3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth ]

Full Idea

Getting from a Tarskian definition of truth to a substantive account of the semantic properties of the object language may involve as little as the reintroduction of a primitive notion of truth.

Gist of Idea

We can get a substantive account of Tarski's truth by adding primitive 'true' to the object language

Source

John Etchemendy (Tarski on Truth and Logical Consequence [1988], p.60), quoted by Donald Davidson - Truth and Predication 1

Book Ref

Davidson,Donald: 'Truth and Predication' [Belknap Harvard 2005], p.24


A Reaction

This is, I think, the first stage in modern developments of axiomatic truth theories. The first problem would be to make sure you haven't reintroduced the Liar Paradox. You need axioms to give behaviour to the 'true' predicate.


The 35 ideas with the same theme [theories of truth built from a set of axioms]:

Ockham had an early axiomatic account of truth [William of Ockham, by Halbach]
If axioms and their implications have no contradictions, they pass my criterion of truth and existence [Hilbert]
We need an undefined term 'true' in the meta-language, specified by axioms [Tarski]
Tarski's had the first axiomatic theory of truth that was minimally adequate [Tarski, by Horsten]
Tarski defined truth, but an axiomatisation can be extracted from his inductive clauses [Tarski, by Halbach]
Tarski thought axiomatic truth was too contingent, and in danger of inconsistencies [Tarski, by Davidson]
We can elucidate indefinable truth, but showing its relation to other concepts [Davidson]
Certain three-valued languages can contain their own truth predicates [Kripke, by Gupta]
The Tarskian move to a metalanguage may not be essential for truth theories [Kripke, by Gupta]
We can get a substantive account of Tarski's truth by adding primitive 'true' to the object language [Etchemendy]
'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten]
Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten]
The Naďve Theory takes the bi-conditionals as axioms, but it is inconsistent, and allows the Liar [Horsten]
Axiomatic theories take truth as primitive, and propose some laws of truth as axioms [Horsten]
A good theory of truth must be compositional (as well as deriving biconditionals) [Horsten]
By adding truth to Peano Arithmetic we increase its power, so truth has mathematical content! [Horsten]
An axiomatic theory needs to be of maximal strength, while being natural and sound [Horsten]
Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [Horsten]
Axiomatic truth doesn't presuppose a truth-definition, though it could admit it at a later stage [Halbach]
The main semantic theories of truth are Kripke's theory, and revisions semantics [Halbach]
Gödel numbering means a theory of truth can use Peano Arithmetic as its base theory [Halbach]
Truth axioms need a base theory, because that is where truth issues arise [Halbach]
We know a complete axiomatisation of truth is not feasible [Halbach]
To axiomatise Tarski's truth definition, we need a binary predicate for his 'satisfaction' [Halbach]
A theory is 'conservative' if it adds no new theorems to its base theory [Halbach, by PG]
The Tarski Biconditional theory TB is Peano Arithmetic, plus truth, plus all Tarski bi-conditionals [Halbach]
Compositional Truth CT has the truth of a sentence depending of the semantic values of its constituents [Halbach]
CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [Halbach]
Theories of truth are 'typed' (truth can't apply to sentences containing 'true'), or 'type-free' [Halbach]
Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach]
Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach]
Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach]
If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach]
A natural theory of truth plays the role of reflection principles, establishing arithmetic's soundness [Halbach/Leigh]
If deflationary truth is not explanatory, truth axioms should be 'conservative', proving nothing new [Halbach/Leigh]