7 ideas
17818 | 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. |
17822 | 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... |
17817 | 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. |
17815 | 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') |
17821 | 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. |
19284 | Asserting a necessity just expresses our inability to imagine it is false [Blackburn] |
Full Idea: To say that we dignify a truth as necessary we are expressing our own mental attitudes - our own inability to make anything of a possible way of thinking which denies it. It is this blank unimaginability which we voice when we use the modal vocabulary. | |
From: Simon Blackburn (Spreading the Word [1984], 6.5) | |
A reaction: Yes, but why are we unable to imagine it? I accept that the truth or falsity of Goldbach's Conjecture may well be necessary, but I have no imagination one way or the other about it. Philosophers like Blackburn are very alien to me! |
4375 | Evaluations are not disguised emotions; instead, emotion is a type of evaluation [Achtenberg] |
Full Idea: The emotivist gets things backwards: evaluations are not disguised emotions; instead, emotions are types of evaluation. | |
From: Deborah Achtenberg (Cognition of Value in Aristotle's Ethics [2002], 6.1) | |
A reaction: A nice comment, though a bit optimistic. It is certainly a valuable corrective to emotivist to pin down the cognitive and evaluative aspects of emotion, rather than regarding them as 'raw' feelings. |