Combining Texts

All the ideas for 'Leibniz: Guide for the Perplexed', 'Hilbert's Programme' and 'Analyzing Modality'

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18 ideas

5. Theory of Logic / G. Quantification / 3. Objectual Quantification
'All horses' either picks out the horses, or the things which are horses [Jubien]
     Full Idea: Two ways to see 'all horses are animals' are as picking out all the horses (so that it is a 'horse-quantifier'), ..or as ranging over lots of things in addition to horses, with 'horses' then restricting the things to those that satisfy 'is a horse'.
     From: Michael Jubien (Analyzing Modality [2007], 2)
     A reaction: Jubien says this gives you two different metaphysical views, of a world of horses etc., or a world of things which 'are horses'. I vote for the first one, as the second seems to invoke an implausible categorical property ('being a horse'). Cf Idea 11116.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Gödel showed that the syntactic approach to the infinite is of limited value [Kreisel]
     Full Idea: Usually Gödel's incompleteness theorems are taken as showing a limitation on the syntactic approach to an understanding of the concept of infinity.
     From: Georg Kreisel (Hilbert's Programme [1958], 05)
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
The study of mathematical foundations needs new non-mathematical concepts [Kreisel]
     Full Idea: It is necessary to use non-mathematical concepts, i.e. concepts lacking the precision which permit mathematical manipulation, for a significant approach to foundations. We currently have no concepts of this kind which we can take seriously.
     From: Georg Kreisel (Hilbert's Programme [1958], 06)
     A reaction: Music to the ears of any philosopher of mathematics, because it means they are not yet out of a job.
9. Objects / A. Existence of Objects / 1. Physical Objects
Being a physical object is our most fundamental category [Jubien]
     Full Idea: Being a physical object (as opposed to being a horse or a statue) really is our most fundamental category for dealing with the external world.
     From: Michael Jubien (Analyzing Modality [2007], 2)
     A reaction: This raises the interesting question of why any categories should be considered to be more 'fundamental' than others. I can only think that we perceive something to be an object fractionally before we (usually) manage to identify it.
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
Haecceities implausibly have no qualities [Jubien]
     Full Idea: Properties of 'being such and such specific entity' are often called 'haecceities', but this term carries the connotation of non-qualitativeness which I don't favour.
     From: Michael Jubien (Analyzing Modality [2007], 2)
     A reaction: The way he defines it makes it sound as if it was a category, but I take it to be more like a bare individual essence. If it has not qualities then it has no causal powers, so there could be no evidence for its existence.
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
Substance needs independence, unity, and stability (for individuation); also it is a subject, for predicates [Perkins]
     Full Idea: For individuation, substance needs three properties: independence, to separate it from other things; unity, to call it one thing, rather than an aggregate; and permanence or stability over time. Its other role is as subject for predicates.
     From: Franklin Perkins (Leibniz: Guide for the Perplexed [2007], 3.1)
     A reaction: Perkins is describing the Aristotelian view, which is taken up by Leibniz. 'Substance' is not a controversial idea, if we see that it only means that the world is full of 'things'. It is an unusual philosopher wholly totally denies that.
10. Modality / A. Necessity / 11. Denial of Necessity
De re necessity is just de dicto necessity about object-essences [Jubien]
     Full Idea: I suggest that the de re is to be analyzed in terms of the de dicto. ...We have a case of modality de re when (and only when) the appropriate property in the de dicto formulation is an object-essence.
     From: Michael Jubien (Analyzing Modality [2007], 5)
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modal propositions transcend the concrete, but not the actual [Jubien]
     Full Idea: Where modal propositions may once have seemed to transcend the actual, they now seem only to transcend the concrete.
     From: Michael Jubien (Analyzing Modality [2007], 4)
     A reaction: This is because Jubien has defended a form of platonism. Personally I take modal propositions to be perceptible in the concrete world, by recognising the processes involved, not the mere static stuff.
Your properties, not some other world, decide your possibilities [Jubien]
     Full Idea: The possibility of your having been a playwright has nothing to do with how people are on other planets, whether in our own or in some other realm. It is only to do with you and the relevant property.
     From: Michael Jubien (Analyzing Modality [2007], 1)
     A reaction: I'm inclined to think that this simple point is conclusive disproof of possible worlds as an explanation of modality (apart from Jubien's other nice points). What we need to understand are modal properties, not other worlds.
Modal truths are facts about parts of this world, not about remote maximal entities [Jubien]
     Full Idea: Typical modal truths are just facts about our world, and generally facts about very small parts of it, not facts about some infinitude of complex, maximal entities.
     From: Michael Jubien (Analyzing Modality [2007], 1)
     A reaction: I think we should embrace this simple fact immediately, and drop all this nonsense about possible worlds, even if they are useful for the semantics of modal logic.
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
We have no idea how many 'possible worlds' there might be [Jubien]
     Full Idea: As soon as we start talking about 'possible world', we beg the question of their relevance to our prior notion of possibility. For all we know, there are just two such realms, or twenty-seven, or uncountably many, or even set-many.
     From: Michael Jubien (Analyzing Modality [2007], 1)
If there are no other possible worlds, do we then exist necessarily? [Jubien]
     Full Idea: Suppose there happen to be no other concrete realms. Would we happily accept the consequence that we exist necessarily?
     From: Michael Jubien (Analyzing Modality [2007], 1)
If all possible worlds just happened to include stars, their existence would be necessary [Jubien]
     Full Idea: If all of the possible worlds happened to include stars, how plausible is it to think that if this is how things really are, then we've just been wrong to regard the existence of stars as contingent?
     From: Michael Jubien (Analyzing Modality [2007], 1)
Possible worlds just give parallel contingencies, with no explanation at all of necessity [Jubien]
     Full Idea: In the world theory, what passes for 'necessity' is just a bunch of parallel 'contingencies'. The theory provides no basis for understanding why these contingencies repeat unremittingly across the board (while others do not).
     From: Michael Jubien (Analyzing Modality [2007], 1)
If other worlds exist, then they are scattered parts of the actual world [Jubien]
     Full Idea: Any other realms that happened to exist would just be scattered parts of the actual world, not entire worlds at all. It would just happen that physical reality was fragmented in this remarkable but modally inconsequential way.
     From: Michael Jubien (Analyzing Modality [2007], 1)
     A reaction: This is aimed explicitly at Lewis's modal realism, and strikes me as correct. Jubien's key point here is that they are irrelevant to modality, just as foreign countries are irrelevant to the modality of this one.
Worlds don't explain necessity; we use necessity to decide on possible worlds [Jubien]
     Full Idea: The suspicion is that the necessity doesn't arise from how worlds are, but rather that the worlds are taken to be as they are in order to capture the intuitive necessity.
     From: Michael Jubien (Analyzing Modality [2007], 1)
     A reaction: It has always seemed to me rather glaring that you need a prior notion of 'possible' before you can start to talk about 'possible worlds', but I have always been too timid to disagree with the combination of Saul Kripke and David Lewis. Thank you, Jubien!
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
We mustn't confuse a similar person with the same person [Jubien]
     Full Idea: If someone similar to Humphrey won the election, that nicely establishes the possibility of someone's winning who is similar to Humphrey. But we mustn't confuse this possibility with the intuitively different possibility of Humphrey himself winning.
     From: Michael Jubien (Analyzing Modality [2007], 1)
27. Natural Reality / C. Space / 3. Points in Space
The natural conception of points ducks the problem of naming or constructing each point [Kreisel]
     Full Idea: In analysis, the most natural conception of a point ignores the matter of naming the point, i.e. how the real number is represented or by what constructions the point is reached from given points.
     From: Georg Kreisel (Hilbert's Programme [1958], 13)
     A reaction: This problem has bothered me. There are formal ways of constructing real numbers, but they don't seem to result in a name for each one.