7 ideas
| 23367 | Even pointing a finger should only be done for a reason [Epictetus] |
| Full Idea: Philosophy says it is not right even to stretch out a finger without some reason. | |
| From: Epictetus (fragments/reports [c.57], 15) | |
| A reaction: The key point here is that philosophy concerns action, an idea on which Epictetus is very keen. He rather despise theory. This idea perfectly sums up the concept of the wholly rational life (which no rational person would actually want to live!). |
| 15327 | 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. |
| 15343 | 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. |
| 14966 | 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] |
| 14967 | 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'. |
| 16328 | 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 |
| 17699 | Variables are auxiliary notions, and not part of the 'eternal' essence of logic [Schönfinkel] |
| Full Idea: A variable in a proposition of logic ....has the status of a mere auxiliary notion that is really inappropriate to the constant, 'eternal' essence of the propositions of logic. | |
| From: Moses Schönfinkel (Building Blocks of Mathematical Logic [1924], §1) | |
| A reaction: He presumably thinks that what the variables stand for (and he mentions 'argument places' and 'operators') will be included in the essence. My attention was caught by the thought that he takes logic to have an essence. |