Combining Texts

All the ideas for 'Precis of 'Limits of Abstraction'', 'Oldest System Prog. of German Idealism' and 'Sets and Numbers'

unexpand these ideas     |    start again     |     specify just one area for these texts


13 ideas

2. Reason / A. Nature of Reason / 1. On Reason
Highest reason is aesthetic, and truth and good are subordinate to beauty [Hegel]
     Full Idea: I am now convinced that the highest act of reason, which embraces all ideas, is an aesthetic act, and that truth and goodness are brothers only in beauty.
     From: Georg W.F.Hegel (Oldest System Prog. of German Idealism [1796]), quoted by Simon Critchley - Continental Philosophy - V. Short Intro Append
     A reaction: This seems to be the distinctive value framework of the romantic movement and the nineteenth century, where art is destined to replace religion. However, Plato in the Symposium is an interesting ally. Aim for beauty, and the rest follows?
2. Reason / D. Definition / 2. Aims of Definition
Definitions concern how we should speak, not how things are [Fine,K]
     Full Idea: Our concern in giving a definition is not to say how things are by to say how we wish to speak
     From: Kit Fine (Precis of 'Limits of Abstraction' [2005], p.310)
     A reaction: This sounds like an acceptable piece of wisdom which arises out of analytical and linguistic philosophy. It puts a damper on the Socratic dream of using definition of reveal the nature of reality.
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
The master science is physical objects divided into sets [Maddy]
     Full Idea: The master science can be thought of as the theory of sets with the entire range of physical objects as ur-elements.
     From: Penelope Maddy (Sets and Numbers [1981], II)
     A reaction: This sounds like Quine's view, since we have to add sets to our naturalistic ontology of objects. It seems to involve unrestricted mereology to create normal objects.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / d. Hume's Principle
If Hume's Principle can define numbers, we needn't worry about its truth [Fine,K]
     Full Idea: Neo-Fregeans have thought that Hume's Principle, and the like, might be definitive of number and therefore not subject to the usual epistemological worries over its truth.
     From: Kit Fine (Precis of 'Limits of Abstraction' [2005], p.310)
     A reaction: This seems to be the underlying dream of logicism - that arithmetic is actually brought into existence by definitions, rather than by truths derived from elsewhere. But we must be able to count physical objects, as well as just counting numbers.
Hume's Principle is either adequate for number but fails to define properly, or vice versa [Fine,K]
     Full Idea: The fundamental difficulty facing the neo-Fregean is to either adopt the predicative reading of Hume's Principle, defining numbers, but inadequate, or the impredicative reading, which is adequate, but not really a definition.
     From: Kit Fine (Precis of 'Limits of Abstraction' [2005], p.312)
     A reaction: I'm not sure I understand this, but the general drift is the difficulty of building a system which has been brought into existence just by definition.
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory (unlike the Peano postulates) can explain why multiplication is commutative [Maddy]
     Full Idea: If you wonder why multiplication is commutative, you could prove it from the Peano postulates, but the proof offers little towards an answer. In set theory Cartesian products match 1-1, and n.m dots when turned on its side has m.n dots, which explains it.
     From: Penelope Maddy (Sets and Numbers [1981], II)
     A reaction: 'Turning on its side' sounds more fundamental than formal set theory. I'm a fan of explanation as taking you to the heart of the problem. I suspect the world, rather than set theory, explains the commutativity.
Standardly, numbers are said to be sets, which is neat ontology and epistemology [Maddy]
     Full Idea: The standard account of the relationship between numbers and sets is that numbers simply are certain sets. This has the advantage of ontological economy, and allows numbers to be brought within the epistemology of sets.
     From: Penelope Maddy (Sets and Numbers [1981], III)
     A reaction: Maddy votes for numbers being properties of sets, rather than the sets themselves. See Yourgrau's critique.
Numbers are properties of sets, just as lengths are properties of physical objects [Maddy]
     Full Idea: I propose that ...numbers are properties of sets, analogous, for example, to lengths, which are properties of physical objects.
     From: Penelope Maddy (Sets and Numbers [1981], III)
     A reaction: Are lengths properties of physical objects? A hole in the ground can have a length. A gap can have a length. Pure space seems to contain lengths. A set seems much more abstract than its members.
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Sets exist where their elements are, but numbers are more like universals [Maddy]
     Full Idea: A set of things is located where the aggregate of those things is located, ...but a number is simultaneously located at many different places (10 in my hand, and a baseball team) ...so numbers seem more like universals than particulars.
     From: Penelope Maddy (Sets and Numbers [1981], III)
     A reaction: My gut feeling is that Maddy's master idea (of naturalising sets by building them from ur-elements of natural objects) won't work. Sets can work fine in total abstraction from nature.
Number theory doesn't 'reduce' to set theory, because sets have number properties [Maddy]
     Full Idea: I am not suggesting a reduction of number theory to set theory ...There are only sets with number properties; number theory is part of the theory of finite sets.
     From: Penelope Maddy (Sets and Numbers [1981], V)
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
If mathematical objects exist, how can we know them, and which objects are they? [Maddy]
     Full Idea: The popular challenges to platonism in philosophy of mathematics are epistemological (how are we able to interact with these objects in appropriate ways) and ontological (if numbers are sets, which sets are they).
     From: Penelope Maddy (Sets and Numbers [1981], I)
     A reaction: These objections refer to Benacerraf's two famous papers - 1965 for the ontology, and 1973 for the epistemology. Though he relied too much on causal accounts of knowledge in 1973, I'm with him all the way.
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Number words are unusual as adjectives; we don't say 'is five', and numbers always come first [Maddy]
     Full Idea: Number words are not like normal adjectives. For example, number words don't occur in 'is (are)...' contexts except artificially, and they must appear before all other adjectives, and so on.
     From: Penelope Maddy (Sets and Numbers [1981], IV)
     A reaction: [She is citing Benacerraf's arguments]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
An abstraction principle should not 'inflate', producing more abstractions than objects [Fine,K]
     Full Idea: If an abstraction principle is going to be acceptable, then it should not 'inflate', i.e. it should not result in there being more abstracts than there are objects. By this mark Hume's Principle will be acceptable, but Frege's Law V will not.
     From: Kit Fine (Precis of 'Limits of Abstraction' [2005], p.307)
     A reaction: I take this to be motivated by my own intuition that abstract concepts had better be rooted in the world, or they are not worth the paper they are written on. The underlying idea this sort of abstraction is that it is 'shared' between objects.