gilbert@cs.glasgow.ac.uk (Gilbert Cockton) (07/18/88)
In article <442@ns.ns.com> logajan@ns.ns.com (John Logajan x3118) writes: >My point is that unproveable theories aren't very useful. a) most of your theories of interpersonal interaction, which you use whenever you interact with someone, will be unproven, and unproveable, if only for practical reasons. b) as a lapsed historian, may I recommend that you study the history of ideas and religion. You will find that scientific theories, sanctified by science's notions of "proof" don't even account for 1% of the "theories" which have driven historical changes. I don't know what you mean by "useful", and suspect that you have not spent too long worrying about it either. I suggest you reflect over your last few days and list the decisions you have made as a result of scientific theory, and the decisions which you've had to make by magic because the scientists have not sorted out all the world for you yet. I think most of your decisions will fall into the non-scientific, unproveable category. Now are the theories which are guiding you each day really that useless? -- Gilbert Cockton, Department of Computing Science, The University, Glasgow gilbert@uk.ac.glasgow.cs <europe>!ukc!glasgow!gilbert The proper object of the study of humanity is humans, not machines
logajan@ns.UUCP (John Logajan x3118) (07/22/88)
gilbert@cs.glasgow.ac.uk (Gilbert Cockton) writes: > logajan@ns.UUCP (John Logajan x3118) writes: > >unproveable theories aren't very useful. > most of your theories [...] will be unproven, > and unproveable, if only for practical reasons. Theories that are by their nature unproveable are completely different from theories that are as of yet unproven. Unproveable theories are rather special in that they usually only occur to philosophers, and have little to do with day to day life. You went on and on about unproven theories but failed to deal with the actual subject, namely unproveable theories. Please explain to me how an unproveable theory (one that makes no unique predictions) can be useful? - John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 - - {...rutgers!dayton, ...amdahl!ems, ...uunet!rosevax} !umn-cs!ns!logajan -
maddoxt@novavax.UUCP (Thomas Maddox) (07/24/88)
In article <531@ns.UUCP> logajan@ns.UUCP (John Logajan x3118) writes: >gilbert@cs.glasgow.ac.uk (Gilbert Cockton) writes: >> logajan@ns.UUCP (John Logajan x3118) writes: [Cockton] >> most of your theories [...] will be unproven, >> and unproveable, if only for practical reasons. [Logajan] >Theories that are by their nature unproveable are completely different from >theories that are as of yet unproven. I believe that Gilbert Cockton is not discriminating between assumptions (and their close relatives, hypotheses) and theories, proven or otherwise. John Loganjan's comment comes in at a higher conceptual level where one presumes the assumption/theory distinction has been made.
rjb1@bunny.UUCP (Richard J. Brandau) (07/24/88)
> gilbert@cs.glasgow.ac.uk (Gilbert Cockton) writes: > Please explain to me how an unproveable theory (one that makes no unique > predictions) can be useful? Perhaps you mean a NONDISPROVABLE theory. An "unproveable" theory is a very special thing, often much harder to find than a "proveable" theory. If you can show that a theory is unprovable (in some axiom set), you've done a good day's science. No theories make "unique predictions" about the real, (empirical) world. Are quarks the ONLY way to explain the proliferation of subnuclear particles? Perhaps a god of the cyclotron made them appear. The difference between the scientific and religious theories is that the scientific one can be DISproven: it makes predictions that can be TESTED. You may, if you like, apply this distiction to the beliefs that determine your behavior. Since you can't disprove the existence of God, you may choose to chuck out all religion. Since you CAN think of ways to disprove f=ma, you may avoid being run over by a bus. -- Rich Brandau | I take no responsiblity for the words or deeds of my employer, and | vice versa. Symbolics is a trademark of Symbolics, Inc. UNIX is a | trademark of AT&T. Edsel is a trademark of the Ford Motor Company.
bph@buengc.BU.EDU (Blair P. Houghton) (07/25/88)
In article <531@ns.UUCP> logajan@ns.UUCP (John Logajan x3118) writes: >gilbert@cs.glasgow.ac.uk (Gilbert Cockton) writes: >> logajan@ns.UUCP (John Logajan x3118) writes: >> >unproveable theories aren't very useful. > >> most of your theories [...] will be unproven, >> and unproveable, if only for practical reasons. > >Theories that are by their nature unproveable are completely different from >theories that are as of yet unproven. Unproveable theories are rather >special in that they usually only occur to philosophers, and have little to >do with day to day life. You went on and on about unproven theories but failed >to deal with the actual subject, namely unproveable theories. > >Please explain to me how an unproveable theory (one that makes no unique >predictions) can be useful? > Rudy Carnap wrote _The Logical Syntax of Language_ in 1937. In it he described the development of an all-encompassing, even recursive syntax that could be used to implement logic without bound. One of the simplest examples of unproveability is the paradox "This sentence is false." It drives you nuts if you analyze it semantically; but, it's blithering at a very low level if you hit it with logic: call the sentence S; the sentence then says "If S then not-S." Even a little kid can see that such a thing is patent nonsense. The words in the sentence--the semantics--confuse the issue; while both sentences say exactly the same thing in different semantics. Carnap's thesis in the book was of course that the logic of communication is in the syntax, not the semantics. I'm correcting myself: now that I look at it, the paradox really says "S = not-S." Carnap's mistake (what makes him horribly obscure these days) is that he did all of this amongst a sea of bizarre symbolic definitions designed as an example of the derivation of his syntactical language; but he did it, and it's a definition of _everything_ necessary to carry on a logical calculus without running into walls of description. It even defines itself without resorting to outside means; sort of like writing a C compiler in C without ever having to write one in assembly, and running it on itself to produce the runnable code. Of course, the computer is a semantic thing... I would hope some stout-hearted scientists would apply this sort of thing to unproveable theories; we might find out about god, after all. --Blair "To be, or not to be; that requires one TTL gate at a minimum, but you could do it with three NAND-gates, or just hook the output to Vcc."
cik@l.cc.purdue.edu (Herman Rubin) (07/25/88)
In article <6032@bunny.UUCP>, rjb1@bunny.UUCP (Richard J. Brandau) writes: > > gilbert@cs.glasgow.ac.uk (Gilbert Cockton) writes: > > Please explain to me how an unproveable theory (one that makes no unique > > predictions) can be useful? < Perhaps you mean a NONDISPROVABLE theory. An "unproveable" theory is < a very special thing, often much harder to find than a "proveable" < theory. If you can show that a theory is unprovable (in some axiom < set), you've done a good day's science. > No theories make "unique predictions" about the real, (empirical) > world. Are quarks the ONLY way to explain the proliferation of > subnuclear particles? Perhaps a god of the cyclotron made them > appear. The difference between the scientific and religious theories > is that the scientific one can be DISproven: it makes predictions that > can be TESTED. > > You may, if you like, apply this distiction to the beliefs that > determine your behavior. Since you can't disprove the existence of > God, you may choose to chuck out all religion. Since you CAN think of > ways to disprove f=ma, you may avoid being run over by a bus. It is recognized that any non-trivial complete theory cannot be exactly true. If I say that there will be some history of the universe, this is a trivial untestable theory, and is completely useless. If I say that the motion of the planets is describable by Newton's law of gravity, this is clearly false, but is quite adequate for spaceship navigation. Even with relativistic corrections it is false, because it ignores such things as tidal friction. Furthermore, we do not know the precise form of gravitation in a relativistic framework, and even less the modifications due to quantum mechanical considera- tions. In the strict sense, we will never have a correct theory. The proper question about a theory is whether its errors should be ignored at the present time. And it is quite possible that for some purposes they should and for others they should not. But unless the theory provides predictive power or insight, its accuracy is unimportant. -- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907 Phone: (317)494-6054 hrubin@l.cc.purdue.edu (Internet, bitnet, UUCP)
gilbert@cs.glasgow.ac.uk (Gilbert Cockton) (07/27/88)
In article <531@ns.UUCP> logajan@ns.UUCP (John Logajan x3118) writes: >Please explain to me how an unproveable theory (one that makes no unique >predictions) can be useful? > Because people use them. Have a look at the social cognition literature. I understood your argument as saying that non-scientific theories (a.k.a assumptions) cannot be useful, and conversely, that the only useful theories are scientific ones. If my understanding is correct, then this is very narrow minded and smacks of epistemelogical bigotry which no-one can possibly match up to in their day to day interactions. Utility must not be confounded with one text-book epistemology. -- Gilbert Cockton, Department of Computing Science, The University, Glasgow gilbert@uk.ac.glasgow.cs <europe>!ukc!glasgow!gilbert
sierch@well.UUCP (Michael Sierchio) (07/30/88)
Theories are not for proving!
A theory is a model, a description, an attempt to preserve and describe
phenomena -- science is not concerned with "proving" or "disproving"
theories. Proof may have a slightly different meaning for attorneys than
for mathematicians, but scientists are closer to the mathematician's
definition -- when they use the word at all.
A theory may or may not adequately describe the phenomena in question, in
which case it is a "good" or "bad" theory -- of two "good" theories, the
theory that is "more elegant" or "simpler" may be preferred -- but this
is an aesthetic or performance judgement, and again has nothing to do with
proof.
Demonstration and experimentation show (to one degree or another) the value
of a particular theory in a particular domain -- but PROOF? bah!
--
Michael Sierchio @ Small Systems Solutions
sierch@well.UUCP
{pacbell,hplabs,ucbvax,hoptoad}!well!sierch