Combining Texts

All the ideas for 'fragments/reports', 'Investigations into Logical Deduction' and 'Outline of a Theory of Truth'

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8 ideas

3. Truth / F. Semantic Truth / 2. Semantic Truth
Kripke's semantic theory has actually inspired promising axiomatic theories [Kripke, by Horsten]
     Full Idea: Kripke has a semantic theory of truth which has inspired promising axiomatic theories of truth.
     From: report of Saul A. Kripke (Outline of a Theory of Truth [1975]) by Leon Horsten - The Tarskian Turn 01.2
     A reaction: Feferman produced an axiomatic version of Kripke's semantic theory.
Kripke offers a semantic theory of truth (involving models) [Kripke, by Horsten]
     Full Idea: One of the most popular semantic theories of truth is Kripke's theory. It describes a class of models which themselves involve a truth predicate (unlike Tarski's semantic theory).
     From: report of Saul A. Kripke (Outline of a Theory of Truth [1975]) by Leon Horsten - The Tarskian Turn 02.3
     A reaction: The modern versions explored by Horsten are syntactic versions of this, derived from Feferman's axiomatisation of the Kripke theory.
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
The Tarskian move to a metalanguage may not be essential for truth theories [Kripke, by Gupta]
     Full Idea: Kripke established that, contrary to the prevalent Tarskian dogma, attributions of truth do not always force a move to a metalanguage.
     From: report of Saul A. Kripke (Outline of a Theory of Truth [1975], 5.1) by Anil Gupta - Truth
     A reaction: [Gupta also cites Martin and Woodruff 1975]
Certain three-valued languages can contain their own truth predicates [Kripke, by Gupta]
     Full Idea: Kripke showed via a fixed-point argument that certain three-valued languages can contain their own truth predicates.
     From: report of Saul A. Kripke (Outline of a Theory of Truth [1975]) by Anil Gupta - Truth
     A reaction: [Gupta also cites Martin and Woodruff 1975] It is an odd paradox that truth can only be included if one adds a truth-value of 'neither true nor false'. The proposed three-valued system is 'strong Kleene logic'.
3. Truth / G. Axiomatic Truth / 3. KF Truth Axioms
Kripke classified fixed points, and illuminated their use for clarifications [Kripke, by Halbach]
     Full Idea: Kripke's main contribution was …his classification of the different consistent fixed points and the discussion of their use for discriminating between ungrounded sentences, paradoxical sentences, and so on.
     From: report of Saul A. Kripke (Outline of a Theory of Truth [1975]) by Volker Halbach - Axiomatic Theories of Truth 15.1
5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking]
     Full Idea: Gentzen thought that his natural deduction gets at the heart of logical reasoning, and used the sequent calculus only as a convenient tool for proving his chief results.
     From: report of Gerhard Gentzen (Investigations into Logical Deduction [1935]) by Ian Hacking - What is Logic? §05
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
     Full Idea: Archelaus was the first person to say that the universe is boundless.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]
     Full Idea: Archelaus wrote that life on Earth began in a primeval slime.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus
     A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea.