Combining Texts

All the ideas for 'Phenomenalism', 'Psychophysical and theoretical identifications' and 'Constructibility and Mathematical Existence'

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9 ideas

4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
We could talk of open sentences, instead of sets [Chihara, by Shapiro]
     Full Idea: Chihara's programme is to replace talk of sets with talk of open sentences. Instead of speaking of the set of all cats, we talk about the open sentence 'x is a cat'.
     From: report of Charles Chihara (Constructibility and Mathematical Existence [1990]) by Stewart Shapiro - Thinking About Mathematics 9.2
     A reaction: As Shapiro points out, this is following up Russell's view that sets should be replaced with talk of properties. Chihara is expressing it more linguistically. I'm in favour of any attempt to get rid of sets.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Chihara's system is a variant of type theory, from which he can translate sentences [Chihara, by Shapiro]
     Full Idea: Chihara's system is a version of type theory. Translate thus: replace variables of sets of type n with level n variables over open sentences, replace membership/predication with satisfaction, and high quantifiers with constructability quantifiers.
     From: report of Charles Chihara (Constructibility and Mathematical Existence [1990]) by Stewart Shapiro - Philosophy of Mathematics 7.4
We can replace type theory with open sentences and a constructibility quantifier [Chihara, by Shapiro]
     Full Idea: Chihara's system is similar to simple type theory; he replaces each type with variables over open sentences, replaces membership (or predication) with satisfaction, and replaces quantifiers over level 1+ variables with constructability quantifiers.
     From: report of Charles Chihara (Constructibility and Mathematical Existence [1990]) by Stewart Shapiro - Thinking About Mathematics 9.2
     A reaction: This is interesting for showing that type theory may not be dead. The revival of supposedly dead theories is the bread-and-butter of modern philosophy.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
Introduce a constructibility quantifiers (Cx)Φ - 'it is possible to construct an x such that Φ' [Chihara, by Shapiro]
     Full Idea: Chihara has proposal a modal primitive, a 'constructability quantifier'. Syntactically it behaves like an ordinary quantifier: Φ is a formula, and x a variable. Then (Cx)Φ is a formula, read as 'it is possible to construct an x such that Φ'.
     From: report of Charles Chihara (Constructibility and Mathematical Existence [1990]) by Stewart Shapiro - Philosophy of Mathematics 7.4
     A reaction: We only think natural numbers are infinite because we see no barrier to continuing to count, i.e. to construct new numbers. We accept reals when we know how to construct them. Etc. Sounds promising to me (though not to Shapiro).
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Modern phenomenalism holds that objects are logical constructions out of sense-data [Ayer]
     Full Idea: Nowadays phenomenalism is held to be a theory of perception which says that physical objects are logical constructions out of sense-data.
     From: A.J. Ayer (Phenomenalism [1947], §1)
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
The concept of sense-data allows us to discuss appearances without worrying about reality [Ayer]
     Full Idea: The introduction of the term 'sense-datum' is a means of referring to appearances without prejudging the question of what it is, if anything, that they are appearances of.
     From: A.J. Ayer (Phenomenalism [1947], §1)
26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory
Laws are the best axiomatization of the total history of world events or facts [Lewis, by Mumford]
     Full Idea: The Mill-Ramsey-Lewis theory takes laws to be axioms (or theorems) of the best possible systematizations of the world's total history, where such a history is a history of events or facts.
     From: report of David Lewis (Psychophysical and theoretical identifications [1972]) by Stephen Mumford - Laws in Nature 1.3
If simplicity and strength are criteria for laws of nature, that introduces a subjective element [Mumford on Lewis]
     Full Idea: Lewis's simplicity and strength criteria introduce an element of subjectivity into the laws, because the best system seems to be determined by what we take to be simple and strong in a system.
     From: comment on David Lewis (Psychophysical and theoretical identifications [1972]) by Stephen Mumford - Laws in Nature 3.5
     A reaction: [Mumford cites Armstrong 1983:67 for this]
A number of systematizations might tie as the best and most coherent system [Mumford on Lewis]
     Full Idea: Since the best system view is a coherence theory, the possibility could not be ruled out that a number of different systematizations of the same history might be tied for first place as equally best.
     From: comment on David Lewis (Psychophysical and theoretical identifications [1972]) by Stephen Mumford - Laws in Nature 3.5
     A reaction: [Mumord cites Armstrong 1983:70] Personally I am a fan of coherence theories, and this problem doesn't bother me.