Combining Texts

All the ideas for 'fragments/reports', 'Truth' and 'The Structure of Appearance'

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11 ideas

3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Truth rests on Elimination ('A' is true → A) and Introduction (A → 'A' is true) [Gupta]
     Full Idea: The basic principles governing truth are Truth Elimination (sentence A follows from ''A' is true') and the converse Truth Introduction (''A' is true' follows from A), which combine into Tarski's T-schema - 'A' is true if and only if A.
     From: Anil Gupta (Truth [2001], 5.1)
     A reaction: Introduction and Elimination rules are the basic components of natural deduction systems, so 'true' now works in the same way as 'and', 'or' etc. This is the logician's route into truth.
3. Truth / F. Semantic Truth / 2. Semantic Truth
A weakened classical language can contain its own truth predicate [Gupta]
     Full Idea: If a classical language is expressively weakened - for example, by dispensing with negation - then it can contain its own truth predicate.
     From: Anil Gupta (Truth [2001], 5.2)
     A reaction: Thus the Tarskian requirement to move to a metalanguage for truth is only a requirement of a reasonably strong language. Gupta uses this to criticise theories that dispense with the metalanguage.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
Classes are a host of ethereal, platonic, pseudo entities [Goodman]
     Full Idea: I will not willingly use apparatus that peoples the world with a host of ethereal, platonic, pseudo entities.
     From: Nelson Goodman (The Structure of Appearance [1951], II.2), quoted by David Lewis - Parts of Classes 2.1
     A reaction: This represents the big gap that opened up with Goodman's former comrade in arms, Quine. Lewis quotes it in order to ask whether he means ethereal or platonic, as they are very different. I sympathise with Goodman.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Two objects can apparently make up quite distinct arrangements in sets [Goodman, by Burgess/Rosen]
     Full Idea: Goodman argues that the set or class {{a}},{a,b}} is supposed to be distinct from the set or class {{b},{a,b}}, even though both are ultimately constituted from the same a and b.
     From: report of Nelson Goodman (The Structure of Appearance [1951]) by JP Burgess / G Rosen - A Subject with No Object I.A.2.a
     A reaction: I'm with Goodman all the way here, even though it is deeply unfashionable, particularly in the circles I move in. If there are trillion grains of sand on a beach, how many sets are we supposed to be committed to?
4. Formal Logic / G. Formal Mereology / 1. Mereology
The counties of Utah, and the state, and its acres, are in no way different [Goodman]
     Full Idea: A class (counties of Utah) is different neither from the individual (state of Utah) that contains its members, nor from any other class (acres of Utah) whose members exhaust the whole. For nominalists, distinction of entity means distinction of content.
     From: Nelson Goodman (The Structure of Appearance [1951], p.26), quoted by Achille Varzi - Mereology 3.1
     A reaction: This is a nice credo for the nominalist version of mereology. You can still have a mereology that commits you to the wholes as well as the parts. Cf. Lewis in Idea 10660.
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
The Liar reappears, even if one insists on propositions instead of sentences [Gupta]
     Full Idea: There is the idea that the Liar paradox is solved simply by noting that truth is a property of propositions (not of sentences), and the Liar sentence does not express a proposition. But we then say 'I am not now expressing a true proposition'!
     From: Anil Gupta (Truth [2001], 5.1)
     A reaction: Disappointed to learn this, since I think focusing on propositions (which are unambiguous) rather than sentences solves a huge number of philosophical problems.
Strengthened Liar: either this sentence is neither-true-nor-false, or it is not true [Gupta]
     Full Idea: An example of the Strengthened Liar is the following statement SL: 'Either SL is neither-true-nor-false or it is not true'. This raises a serious problem for any theory that assesses the paradoxes to be neither true nor false.
     From: Anil Gupta (Truth [2001], 5.4.2)
     A reaction: If the sentence is either true or false it reduces to the ordinary Liar. If it is neither true nor false, then it is true.
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
If all and only red things were round things, we would need to specify the 'respect' of the resemblance [Goodman, by Macdonald,C]
     Full Idea: According to Goodman's 'companionship difficulty', resemblance nominalism has a problem if, say, all and only the red things were the round things, because we cannot distinguish the two different respects in which the things resemble one another.
     From: report of Nelson Goodman (The Structure of Appearance [1951]) by Cynthia Macdonald - Varieties of Things Ch.6
     A reaction: Goodman opts for extreme linguististic nominalism in response to this (Idea 7952), whereas Russell opts for a sort of Platonism (4441). The current idea gives Russell a further problem, of needing a universal of the respect of the resemblance.
Without respects of resemblance, we would collect blue book, blue pen, red pen, red clock together [Goodman, by Macdonald,C]
     Full Idea: Goodman's 'imperfect community' problem for Resemblance Nominalism says that without mention of respects in which things resemble, we end up with a heterogeneous collection with nothing wholly in common (blue book, blue pen, red pen, red clock).
     From: report of Nelson Goodman (The Structure of Appearance [1951]) by Cynthia Macdonald - Varieties of Things Ch.6
     A reaction: This suggests Wittgenstein's 'family' resemblance as a way out (Idea 4141), but a blue book and a red clock seem totally unrelated. Nice objection! At this point we start to think that the tropes resemble, rather than the objects.
8. Modes of Existence / E. Nominalism / 3. Predicate Nominalism
If we apply the same word to different things, it is only because we are willing to do so [Goodman, by Macdonald,C]
     Full Idea: Predicate nominalism is the view that what all things to which the same word applies have in common is simply our willingness to apply the same word to them.
     From: report of Nelson Goodman (The Structure of Appearance [1951], Ch.6) by Cynthia Macdonald - Varieties of Things
     A reaction: This is Goodman's 'extreme nominalist' position. This seems also to be an anti-realist position, as it denies any 'joints' to nature (Idea 7953). It strikes me as daft. WHY are we willing to apply words in certain ways?
10. Modality / A. Necessity / 8. Transcendental Necessity
Everything happens by reason and necessity [Leucippus]
     Full Idea: Nothing happens at random; everything happens out of reason and by necessity.
     From: Leucippus (fragments/reports [c.435 BCE], B002), quoted by (who?) - where?