Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

SUO: RE: Re^n: Collections - Aggregation or Set




Dear Chris,

> 
> Chris P wrote:
> > Max Black's essay (referred to in an earlier email) starts with a
> > quote from a working mathematician's book on set theory - 
> which claims
> > that packs of wolves etc. are standard examples of sets. 
> 
> A claim that is pretty obviously false.  A pack can change its members
> (if, for example, a pup is born) and remain the same pack.  Not so the
> set corresponding to the pack at any given time.

MW: Not so obviously in fact. You have assumed a 3D ontology, Chris and I
would assume a 4D ontology (I don't know about Max Black). In this case the
set of members of the flock is the spatio-temporal extent of all members of
the flock, past, present and future. This doesn't change over time. 

> 
> > If I had the time, I am sure I could come up with other examples. 
> 
> There are lots of similar examples that go wrong for similar 
> reasons --
> flocks of geese, schools of fish, citizens of a country, sets 
> of dishes,
> etc.  All of these collective entities can change their membership, at
> least to some extent, and remain the same collective entity.  
> Not so the
> corresponding sets at any given time.

MW: These are sets too of course.
> 
> That said, there is one (and only one) clear thinking philosopher of
> mathematics that I know of who has respectably defended (not to say
> demonstrated) the view that sets of physical objects are themselves
> physical, viz., Penelope Maddy.  The locus classicus here is her 1980
> paper "Perception and Mathematical Intuition," Philosophical Review 89
> (1980), pp. 163-196.  Maddy is no crackpot -- she's head of the Logic
> and Philosophy of Science program at UC Irvine, author of two highly
> regarded Oxford Univ Press books on philosophy of mathematics, and she
> is a member of the American Academy of Arts and Sciences.  
> 
> The most interesting thing Maddy does in defense of the physicality
> thesis is to marshall neuroscientific evidence for the existence of
> "set detectors" that enable us to perceive sets of physical objects.
> Such detectors, she argues, if they exist, provide a sound 
> naturalistic
> basis for the possibility of set theoretic knowledge.  After all, if
> sets really *are* completely abstract things, then they are causally
> inert and so (for the naturalist) a question remains as to how we can
> know anything about them.  Maddy, who is both a mathematical realist
> about set theory and a scientific naturalist argues that her appraoch
> fills this epistemological gap.
> 
> Chris Menzel
> 
> 
> 

Regards  
      Matthew
============================================
Matthew West
Operations & Asset Management
Shell Services International
H3229, Shell Centre, London, SE1 7NA, UK.
Tel: +44 207 934 4490 Fax: 7929 
Mobile: +44 7796 336538
E-mail: Matthew.R.West@is.shell.com
http://www.shellservices.com/
============================================