Science, reductionism, & Occam

[Yoshie Furuhashi]

>At 05:08 AM 05/25/2001 -0400, Justin wrote:
>>I am not sure what all this has to do with Occam's razor. The injunction not
>>multiply entities unnecessarily, or, translated into our terms, to choose
>>the simpler of otherwise explanatorily equal theories, is just good
>>scientific practice. It's obviously not an injunction not to avoid
>>explantorily necessary or useful entities and causes. This hasn't anything
>>to do with analytical philosophy or logical positivism. It's just what good
>>scientists do. If you have a specific explanation that calls for posits
>>others reject (say "value" or "class" or whatever), make a case that they
>>are necessary, that they do some work. Then you won;t be violating Occam's
>>razor to posit them. Occam's razor doesn't tell you that you must inhabit an
>>intellectual desert, just that what you plant has to have roots and do work.
>
>"Not multiplying entities unnecessarily" is the most generous 
>interpretation of Occam's razor I have heard. The way it was 
>presented the me in school was more like the principle of the 
>absolute exclusive OR. Something is X _OR_ it is Y. There is no 
>third way. And this way of looking at things, it seems to me, makes 
>it impossible to do a lot of modern physics: is light a wave or is 
>it a particle?
>
>I think I'm with Einstein:   "Make it simple, but not too simple."
>
>Joanna B.

One may think about simplicity in this way: Einstein suggests the 
lower limit of simplicity whereas Occam does the _upper_ limit.

Justin knows what he's talking about:

*****   What is Occam's Razor?

Occam's (or Ockham's) razor is a principle attributed to the 14th 
century logician and Franciscan friar; William of Occam. Ockham was 
the village in the English county of Surrey where he was born.

The principle states that "Entities should not be multiplied 
unnecessarily." Sometimes it is quoted in one of its original Latin 
forms to give it an air of authenticity.

"Pluralitas non est ponenda sine neccesitate"
"Frustra fit per plura quod potest fieri per pauciora"
"Entia non sunt multiplicanda praeter necessitatem"

In fact, only the first two of these forms appear in his surviving 
works and the third was written by a later scholar. William used the 
principle to justify many conclusions including the statement that 
"God's existence can not be deduced by reason alone." That one didn't 
make him very popular with the Pope....

<http://math.ucr.edu/home/baez/physics/occam.html>   *****

Justin's citing the original form.  Later writers often put Occam's 
Razor in forms stronger than the man had intended, thus giving you 
the impression that you've got.

Occam's Razor helps to eliminate scientifically irrelevant 
conjectures (about God, Jewish Conspiracy, etc.) from theorizing.

Yoshie