Combining Texts

All the ideas for '', 'Truth' and 'New Foundations for Mathematical Logic'

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7 ideas

3. Truth / C. Correspondence Truth / 1. Correspondence Truth
True sentences says the appropriate descriptive thing on the appropriate demonstrative occasion [Austin,JL]
     Full Idea: A sentence is said to be true when the historic state of affairs to which it is correlated by the demonstrative conventions (the one to which it 'refers') is of a type with which the sentence used in making it is correlated by the descriptive conventions.
     From: J.L. Austin (Truth [1950], §3)
     A reaction: This is correspondence by convention rather than correspondence by mapping. Personally I prefer some sort of mapping account, despite all the difficulty and vagueness of specifying what maps onto what.
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
Correspondence theorists shouldn't think that a country has just one accurate map [Austin,JL]
     Full Idea: Correspondence theorists too often talk as one would who held that every map is either accurate or inaccurate; that every country can have but one accurate map.
     From: J.L. Austin (Truth [1950], n 24)
     A reaction: A well-made point, for those who intuitively hang on to correspondence as not only good common sense, but also some sort of salvation for a realist view of the world which might give us certainty in epistemology.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
NF has no models, but just blocks the comprehension axiom, to avoid contradictions [Quine, by Dummett]
     Full Idea: Quine's New Foundations system of set theory, devised with no model in mind, but on the basis of a hunch that a purely formal restriction on the comprehension axiom would block all contradictions.
     From: report of Willard Quine (New Foundations for Mathematical Logic [1937]) by Michael Dummett - Frege philosophy of mathematics Ch.18
     A reaction: The point is that Quine (who had an ontological preference for 'desert landscapes') attempted to do without an ontological commitment to objects (and their subsequent models), with a purely formal system. Quine's NF is not now highly regarded.
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]
     Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation.
     From: Ian Rumfitt ("Yes" and "No" [2000], II)
     A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]
     Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table.
     From: Ian Rumfitt ("Yes" and "No" [2000])
     A reaction: This is the standard view which Rumfitt sets out to challenge.
The sense of a connective comes from primitively obvious rules of inference [Rumfitt]
     Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious.
     From: Ian Rumfitt ("Yes" and "No" [2000], III)
     A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value.
19. Language / F. Communication / 3. Denial
We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]
     Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A.
     From: Ian Rumfitt ("Yes" and "No" [2000], IV)
     A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role).