Combining Texts

All the ideas for 'Abstract Objects: a Case Study', 'What is Mathematical Truth?' and 'Probability and Logic of Rational Belief'

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6 ideas

5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / e. The Lottery paradox
If my ticket won't win the lottery (and it won't), no other tickets will either [Kyburg, by Pollock/Cruz]
     Full Idea: The Lottery Paradox says you should rationally conclude that your ticket will not win the lottery, and then apply the same reasoning to all the other tickets, and conclude that no ticket will win the lottery.
     From: report of Henry E. Kyburg Jr (Probability and Logic of Rational Belief [1961]) by J Pollock / J Cruz - Contemporary theories of Knowledge (2nd) §7.2.8
     A reaction: (Very compressed by me). I doubt whether this is a very deep paradox; the conclusion that I will not win is a rational assessment of likelihood, but it is not the result of strict logic.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
Mathematics is both necessary and a priori because it really consists of logical truths [Yablo]
     Full Idea: Mathematics seems necessary because the real contents of mathematical statements are logical truths, which are necessary, and it seems a priori because logical truths really are a priori.
     From: Stephen Yablo (Abstract Objects: a Case Study [2002], 10)
     A reaction: Yablo says his logicism has a Kantian strain, because numbers and sets 'inscribed on our spectacles', but he takes a different view (in the present Idea) from Kant about where the necessity resides. Personally I am tempted by an a posteriori necessity.
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Putting numbers in quantifiable position (rather than many quantifiers) makes expression easier [Yablo]
     Full Idea: Saying 'the number of Fs is 5', instead of using five quantifiers, puts the numeral in quantifiable position, which brings expressive advantages. 'There are more sheep in the field than cows' is an infinite disjunction, expressible in finite compass.
     From: Stephen Yablo (Abstract Objects: a Case Study [2002], 08)
     A reaction: See Hofweber with similar thoughts. This idea I take to be a key one in explaining many metaphysical confusions. The human mind just has a strong tendency to objectify properties, relations, qualities, categories etc. - for expression and for reasoning.
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
Concrete objects have few essential properties, but properties of abstractions are mostly essential [Yablo]
     Full Idea: Objects like me have a few essential properties, and numerous accidental ones. Abstract objects are a different story. The intrinsic properties of the empty set are mostly essential. The relations of numbers are also mostly essential.
     From: Stephen Yablo (Abstract Objects: a Case Study [2002], 01)
We are thought to know concreta a posteriori, and many abstracta a priori [Yablo]
     Full Idea: Our knowledge of concreta is a posteriori, but our knowledge of numbers, at least, has often been considered a priori.
     From: Stephen Yablo (Abstract Objects: a Case Study [2002], 02)
10. Modality / B. Possibility / 1. Possibility
Mathematics eliminates possibility, as being simultaneous actuality in sets [Putnam]
     Full Idea: Mathematics has got rid of possibility by simply assuming that, up to isomorphism anyway, all possibilities are simultaneous actual - actual, that is, in the universe of 'sets'.
     From: Hilary Putnam (What is Mathematical Truth? [1975], p.70), quoted by Stewart Shapiro - Philosophy of Mathematics 7.5