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All the ideas for 'Commentary on 'De Anima'', 'Remarks on the definition and nature of mathematics' and 'Apriority and Existence'

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11 ideas

4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
The main modal logics disagree over three key formulae [Yablo]
     Full Idea: Lewis's different systems of modal logic differed about such formulae as □P implies □□P; ◊□P implies □P; and ◊S implies □◊S
     From: Stephen Yablo (Apriority and Existence [2000], §06)
     A reaction: Yablo's point is that the various version don't seem to make much difference to our practices in logic, mathematics and science. The problem, says Yablo, is deciding exactly what you mean by 'necessarily' and 'possibly'.
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
To study formal systems, look at the whole thing, and not just how it is constructed in steps [Curry]
     Full Idea: In the study of formal systems we do not confine ourselves to the derivation of elementary propositions step by step. Rather we take the system, defined by its primitive frame, as datum, and then study it by any means at our command.
     From: Haskell B. Curry (Remarks on the definition and nature of mathematics [1954], 'The formalist')
     A reaction: This is what may potentially lead to an essentialist view of such things. Focusing on bricks gives formalism, focusing on buildings gives essentialism.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
If 'the number of Democrats is on the rise', does that mean that 50 million is on the rise? [Yablo]
     Full Idea: If someone says 'the number of Democrats is on the rise', he or she wants to focus on Democrats, not numbers. If the number is 50 million, is 50 million really on the rise?
     From: Stephen Yablo (Apriority and Existence [2000], §14)
     A reaction: This is a very nice warning from Yablo, against easy platonism, or any sort of platonism at all. We routinely say that numbers are 'increasing', but the real meaning needs entangling. Here it refers to people joining a party.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
We must treat numbers as existing in order to express ourselves about the arrangement of planets [Yablo]
     Full Idea: It is only by making as if to countenance numbers that one can give expression in English to a fact having nothing to do with numbers, a fact about stars and planets and how they are numerically proportioned.
     From: Stephen Yablo (Apriority and Existence [2000], §13)
     A reaction: To avoid the phrase 'numerically proportioned', he might have alluded to the 'pattern' of the stars and planets. I'm not sure which -ism this is, but it seems to me a good approach. The application is likely to precede the theory.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
It is untenable that mathematics is general physical truths, because it needs infinity [Curry]
     Full Idea: According to realism, mathematical propositions express the most general properties of our physical environment. This is the primitive view of mathematics, yet on account of the essential role played by infinity in mathematics, it is untenable today.
     From: Haskell B. Curry (Remarks on the definition and nature of mathematics [1954], 'The problem')
     A reaction: I resist this view, because Curry's view seems to imply a mad metaphysics. Hilbert resisted the role of the infinite in essential mathematics. If the physical world includes its possibilities, that might do the job. Hellman on structuralism?
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Saying mathematics is logic is merely replacing one undefined term by another [Curry]
     Full Idea: To say that mathematics is logic is merely to replace one undefined term by another.
     From: Haskell B. Curry (Remarks on the definition and nature of mathematics [1954], 'Mathematics')
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Platonic objects are really created as existential metaphors [Yablo]
     Full Idea: The means by which platonic objects are simulated is existential metaphor. Numbers are conjured up as metaphorical measures of cardinality.
     From: Stephen Yablo (Apriority and Existence [2000], §12)
     A reaction: 'Fictional' might be a better word than 'metaphorical', since the latter usually implies some sort of comparison.
7. Existence / D. Theories of Reality / 7. Fictionalism
We quantify over events, worlds, etc. in order to make logical possibilities clearer [Yablo]
     Full Idea: It is not that the contents of sentences are inexpressible without quantifying over events, worlds, etc. (they aren't). But the logical relations become much more tractable if we represent them quantificationally.
     From: Stephen Yablo (Apriority and Existence [2000], §13)
     A reaction: Yablo is explaining why we find ourselves committed to abstract objects. It is essentially, as I am beginning to suspect, a conspiracy of logicians. What on earth is 'the empty set' when it is at home? What's it made of?
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Philosophers keep finding unexpected objects, like models, worlds, functions, numbers, events, sets, properties [Yablo]
     Full Idea: There's a tradition in philosophy of finding 'unexpected objects' in truth-conditions, such as countermodels, possible worlds, functions, numbers, events, sets and properties.
     From: Stephen Yablo (Apriority and Existence [2000], §02)
     A reaction: This is a very nice perspective on the whole matter of abstract objects. If we find ourselves reluctantly committed to the existence of something which is ontologically peculiar, we should go back to the philosophical drawing-board.
19. Language / F. Communication / 6. Interpreting Language / d. Metaphor
Hardly a word in the language is devoid of metaphorical potential [Yablo]
     Full Idea: There is hardly a word in the language - be it an adverb, preposition, conjunction, or what have you - that is devoid of metaphorical potential.
     From: Stephen Yablo (Apriority and Existence [2000], §12)
     A reaction: Yablo goes on to claim that metaphor is at the heart of all of our abstract thinking. 'Dead metaphors' (like the "mouth" of a river) sink totally into literal language. I think Yablo is on the right lines.
22. Metaethics / B. Value / 2. Values / e. Death
The soul conserves the body, as we see by its dissolution when the soul leaves [Toletus]
     Full Idea: Every accident of a living thing, as well as all its organs and temperaments and its dispositions are conserved by the soul. We see this from experience, since when that soul recedes, all these dissolve and become corrupted.
     From: Franciscus Toletus (Commentary on 'De Anima' [1572], II.1.1), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 24.5
     A reaction: A nice example of observing a phenemonon, but not being able to observe the dependence relation the right way round. Compare Descartes in Idea 16763.