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Ideas for 'Sets, Aggregates and Numbers', 'Isolation and Non-arbitrary Division' and 'works'

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9 ideas

6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
Objects do not naturally form countable units [Koslicki]
     Full Idea: Objects do not by themselves naturally fall into countable units.
     From: Kathrin Koslicki (Isolation and Non-arbitrary Division [1997], 2.2)
     A reaction: Hm. This seems to be modern Fregean orthodoxy. Why did the institution of counting ever get started if the things in the world didn't demand counting? Even birds are aware of the number of eggs in their nest (because they miss a stolen one).
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
We can still count squares, even if they overlap [Koslicki]
     Full Idea: The fact that there is overlap does not seem to inhibit our ability to count squares.
     From: Kathrin Koslicki (Isolation and Non-arbitrary Division [1997], 2.2)
     A reaction: She has a diagram of three squares overlapping slightly at their corners. Contrary to Frege, these seems to depend on a subliminal concept of the square that doesn't depend on language.
How many? must first partition an aggregate into sets, and then logic fixes its number [Yourgrau]
     Full Idea: We want to know How many what? You must first partition an aggregate into parts relevant to the question, where no partition is privileged. How the partitioned set is to be numbered is bound up with its unique members, and follows from logic alone.
     From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'New Problem')
     A reaction: [Compressed wording of Yourgrau's summary of Frege's 'relativity argument'] Concepts do the partitioning. Yourgau says this fails, because the same argument applies to the sets themselves, as well as to the original aggregates.
Nothing is 'intrinsically' numbered [Yourgrau]
     Full Idea: Nothing at all is 'intrinsically' numbered.
     From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'What the')
     A reaction: Once you are faced with distinct 'objects' of some sort, they can play the role of 'unit' in counting, so his challenge is that nothing is 'intrinsically' an object, which is the nihilism explored by Unger, Van Inwagen and Merricks. Aristotle disagrees...
There is no deep reason why we count carrots but not asparagus [Koslicki]
     Full Idea: Why do speakers of English count carrots but not asparagus? There is no 'deep' reason.
     From: Kathrin Koslicki (Isolation and Non-arbitrary Division [1997])
     A reaction: Koslick is offering this to defend the Fregean conceptual view of counting, but what seems to matter is what is countable, and not whether we happen to count it. You don't need to know what carrots are to count them. Cooks count asparagus.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / d. Counting via concepts
We struggle to count branches and waves because our concepts lack clear boundaries [Koslicki]
     Full Idea: The reason we have a hard time counting the branches and the waves is because our concepts 'branches on the tree' and 'waves on the ocean' do not determine sufficiently precise boundaries: the concepts do not draw a clear invisible line around each thing.
     From: Kathrin Koslicki (Isolation and Non-arbitrary Division [1997], 2.2)
     A reaction: This is the 'isolation' referred to in Frege.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
Defining 'three' as the principle of collection or property of threes explains set theory definitions [Yourgrau]
     Full Idea: The Frege-Maddy definition of number (as the 'property' of being-three) explains why the definitions of Von Neumann, Zermelo and others work, by giving the 'principle of collection' that ties together all threes.
     From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'A Fregean')
     A reaction: [compressed two or three sentences] I am strongly in favour of the best definition being the one which explains the target, rather than just pinning it down. I take this to be Aristotle's view.
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
We can't use sets as foundations for mathematics if we must await results from the upper reaches [Yourgrau]
     Full Idea: Sets could hardly serve as a foundation for number theory if we had to await detailed results in the upper reaches of the edifice before we could make our first move.
     From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'Two')
You can ask all sorts of numerical questions about any one given set [Yourgrau]
     Full Idea: We can address a set with any question at all that admits of a numerical reply. Thus we can ask of {Carter, Reagan} 'How many feet do the members have?'.
     From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'On Numbering')
     A reaction: This is his objection to the Fregean idea that once you have fixed the members of a set, you have thereby fixed the unique number that belongs with the set.