From: Jeffrey D Koperski <jkopersk@magnus.acs.ohio-state.edu>
Newsgroups: alt.atheism.moderated
Subject: Re: Existence of gods (Atheism FAQ point 7)
Date: Thu, 17 Dec 1992 22:39:57 GMT
Distribution: world
Organization: The Ohio State University

In article <1kFXVB10w165w@mantis.co.uk> mathew <mathew@mantis.co.uk> writes:
>Jeffrey D Koperski <jkopersk@magnus.acs.ohio-state.edu> writes:
>> This "detection criterion" seems to be flawed for indepedent reasons.  It is

>> reminiscent of the Logical Positivist approach to ruling out the
>> "suspect" beliefs in moral and theological facts.  First, any good scientist
>> believes in the existence of entities that are undetectable.
>
>I don't think this is true.  Can you give an example?
>
The examples followed: black holes, etc.

>> Objects outside the cone as well as, say, whatever is inside a black-hole, a
r
>> not dectectable, yet we ascribe existence to them.
>
>I don't think we do.  Certainly I don't think you'd catch anybody
>claiming that theories about the insides of black holes are anything
>other than hypothesis -- not least because last I heard, we haven't
>actually found a live black hole.

You can call such existence claims theories or hypotheses, it matters not.  A 
tentative existence claim is still an existence claim.  In fact, since all 
science is reviseable, all science is tentative, but that's a bit beside the 
point.  I assume you, like most physcists, believe that black holes exist even 
though we have not as yet found one.  If you do not, then I simply appeal to
the majority of experts in the field on this point.  The same theory that led 
to the positing of black holes predicts what exists inside, namely, a highly 
dense neutron star with a mass greater than the Chandrasekhar limit.  Since 
Hawking's book is probably the most readily available to you and others, I 
suggest you see chapter 6.  Chapter 7 goes on to show that there are actually a
large number of particles inside the event horizon of a black hole: half of a
particle-antiparticle pair.

As I look back at your comment, however, I'm afraid your next response will 
make the hypothesis-theory dichotomy do a great deal of work.  If so, the
discusion will take us into important issues in the philosophy of science that
most non-philosophers are not acquainted with.  Since this is my area of
specialization, I don't mind discussing such topics.  I just wanted you (and
others with interests along these lines) to be aware of the philosophically
packed ground we're heading towards.
>
>> Second, numbers, sets, and a host of universals are undetectable when
>> uninstantiated, but many philosophers and most mathematicians believe in the
>> existence of (at least) some mathematical entities (see, for example, Roger
>> Penrose, _The Emporer's New Mind_).
>
>In what sense do philosophers and mathematicians believe in the
>existence of purely mathematical entities?  I'm afraid I'm singularly
>unimpressed by Penrose's book, as were most of my friends...
>
Well, I don't follow Penrose's mathematical platonism either, but the point is
that he and others believe in the existence of such entities.  As for the "in
what sense" question, existence is a primitive notion as far as I can see.  I
can give you examples, but no one will be able to supply you with necessary and
sufficient conditions for existence.  It is not a property that things have.
Entities exist and then may or may not have property P.  I believe that moose,
this chair, and my wife, among other things, exist.  I believe that Santa
Clause, unicorns, and squared circles do not.  I'm afraid that's the best I can
do.  If you are acquainted with formal logic beyond the introductory level,
then I would remind you there is only one kind existential quantifier.  When I
and other philosophers make an existence claim, then I am saying that I
quantify over such entities.

Thank you for your response.  The two I have seen thus far are quite good.

Jeff Koperski
Dept. of Philosophy
Ohio State