Ockham's Razor

[Hegel]

Dictionary.com states that Ockham's Razor states that:
Entia non sunt multiplicanda praeter necessitatem.
Meaning Entities are not multiplied except when mecessary.

However I could not find any proof for this. If anyone could provide the philosophic proof, or a philosophic proof, I would be most grateful.

 

[T'ai Chi]

OR is only a rule of thumb.

If two theories, A (has m assumptions) and B (has n assumptions) both explain event E equally as well, then it OR is simply a rule of thumb to go with the theory A if m is smaller than n.

OR does not say that A is correct, etc., it just recognizes outside facts that A provides the same results as B, and has less assumptions than B, so therefore it is a good idea to stick with A instead of B.

 

[Hegel]

OR is only a rule of thumb.

If two theories, A (has m assumptions) and B (has n assumptions) both explain event E equally as well, then it OR is simply a rule of thumb to go with the theory A if m is smaller than n.

OR does not say that A is correct, etc., it just recognizes outside facts that A provides the same results as B, and has less assumptions than B, so therefore it is a good idea to stick with A instead of B.

However I have seen a lot of people use this in proofs. That is fine if there starting with this as an axiom, but then it is very easy to just state that their proof is worng, by saying this theory is wrong. For example, many people are trying to prove the non-existance of God using Ockham's Razor. This is a fairly big thing to prove, and one which I wouldn't accept with out some backing to the theory.

 

[toddjh]

It's a matter of how it's applied. A lot of people take Occam's Razor the way it's been popularized: "the simplest explanation is the best."

But that's not really the spirit of it. To me, the best example of how Occam's Razor should be applied is the concept of "theistic evolution." You have two competing theories:

1. Biological evolution occurs according to natural laws.

and

2. Biological evolution occurs according to natural laws, and God is orchestrating it all behind the scenes.

Occam's Razor applies because the second theory has an extra hypothesis that adds complexity without granting any new predictive power. There's no need to assume things that are completely irrelevant to the theory.

Jeremy

 

[Pyrian]

Hegel:
That is fine if there starting with this as an axiom, but then it is very easy to just state that their proof is worng, by saying this theory is wrong.

Ockham's Razor should not be used in proofs. It's purpose is more in the formation of hypotheses. It's used to criticize hypotheses - typically hypotheses that add unnecessary complexity.

Hegel:
For example, many people are trying to prove the non-existance of God using Ockham's Razor.

It's worth noting that most of us jumped all over a similar attempt at disproving God in this very forum. Anyway, you have my permission to smack upside the head anyone claiming the Ockham's Razor proves anything.

Besides, disproving God effectively requires defining God first - once you do that step, it tends to be fairly straight forward, at which point anyone arguing simply switches their definition of God. This can be fun for a while - especially if I can push them into defining God in such a way that I can fit either myself or some basic law of physics into the definition - but inevitably gets boring or tangled up in the definitions of something like "all-loving," "omnipotent," or "omniscient." (I'm convinced that in their basic form all three of those are literally self-contradictory.)

 

[Lord Kenneth]

Here is a good example of Occam's Razor:

"Where does lightening come from?"

One could say Zeus does it, or it is caused by natural processes.

Well, massive evidence for the latter aside, we already know natural causes exist, so it is best to assume that rather than creating some unknown being as the cause.

Of course, if we were able to find this Zeus and find out how he creates thunder (that would be difficult!) that would be the most parsimonious explanation, because after that it would take more stretching to say that Zeus doesn't really do it (unless you had evidence of that).

 

[Dancing David]

The razor while useful is just a tool, not all tools work in all situations.

It gets to the notion of elegance, the simpler and more compact a theory the more elegant it is.

And there is the problem with defining simplicity.

A theist would say god does everything.
so this has been used to demonstarte idealism on this board recently by Franko. A god creating the illusion of the world is simpler to a theist than the actual world existing.

A materialist looks at it from the other side and says that the world exists as it is, a god is redundant.

A razor cuts both ways.

 

[Paul C. Anagnostopoulos]

Classic example: I'm discussing evolution and creationism with some folks. One of them is writing a book on "Christian Creationism." I very much doubt that every bit of Christian dogma is necessary to a theory of creationism. Why not a simpler form of creationism that makes minimum supernatural assumptions? (Well, because he's really writing a Christian apologetic.)

~~ Paul

 

[fhios]

Dictionary.com states that Ockham's Razor states that:
Entia non sunt multiplicanda praeter necessitatem.
Meaning Entities are not multiplied except when mecessary.

However I could not find any proof for this. If anyone could provide the philosophic proof, or a philosophic proof, I would be most grateful.

I've read a collection of his writings (translated out of the original latin, of course), and while he never seems to have stated this idea in just so many words, he did apply it agressively to the medival (sp?) world of ideas.
Occam was attempting to prove that all things--dogs, trees and tables for instance--owe their existance to a decision on the part of God--are "radically contingent upon God," in the words of the books commentator. This idea was of course nessecary to prove God's supremacy over the world, but it also contradicted the Aristotlean idea of a world of essences extending themselves into the phyisical world and picking up specific qualities ("accidents" in the terminology of the time; our expression "an accident of birth" stems from this usage) and thus become the individual dogs, trees and tables in our own universe.
To refute the idea of a world of essences, he argued that the mind was easily able to generalize the ideas of dog, tree and table from its experiences with individual ones, and that the idea of a world of essences was, therefore, surplassage, an entity without logical necessity. That was his use of that law.
Did this help?

 

[Hegel]

That helped, but did he have any evidence for it, or was it just a postulate of his theory?

 

[toddjh]

That helped, but did he have any evidence for it, or was it just a postulate of his theory?

I'm not sure what kind of "evidence" a statement like that needs. It's more of a truism, like the weak anthropic principle. It's pretty obvious (to the modern scientific mind) that you shouldn't assume anything that doesn't have any explanatory power.

Jeremy

 

[fhios]

That helped, but did he have any evidence for it, or was it just a postulate of his theory?

It's for use in purely theoretical matters, ones in which no empirical evidence points to one conclusion being superior to another.

 

[RichardR]

many people are trying to prove the non-existance of God using Ockham's Razor. This is a fairly big thing to prove, and one which I wouldn't accept with out some backing to the theory.

You can't prove the non-existence of God using Occam's Razor. You can use Occam's Razor to determine that there is no need to posit the existence of God to explain anything. That's an important difference.

Occam's Razor says don't invent unnecessary entities to explain something that can already be explained using only entities that are known to exist. That is not because Occam's Razor proves the unnecessary entities don't exist. It is because the additional entities are unnecessary inventions. Which means that you are only invoking them because you happen to like the idea, or because they are necessary for some belief system. The problem is, if you ignore Occam's Razor and invent entities which are not supported by evidence, there are an infinite number of entities you can invoke to explain any phenomena. For example, if I drop my pen and it falls to the ground, I can say it is because there are invisible pieces of elastic pulling it down, or I can say there are invisible fairies in the room that are doing it. And that approach leads nowhere.

It is explained quite well here:

 

[csense]

You can't prove the non-existence of God using Occam's Razor. You can use Occam's Razor to determine that there is no need to posit the existence of God to explain anything. That's an important difference.

Occam's Razor says don't invent unnecessary entities to explain something that can already be explained using only entities that are known to exist. That is not because Occam's Razor proves the unnecessary entities don't exist. It is because the additional entities are unnecessary inventions. Which means that you are only invoking them because you happen to like the idea, or because they are necessary for some belief system. The problem is, if you ignore Occam's Razor and invent entities which are not supported by evidence, there are an infinite number of entities you can invoke to explain any phenomena. For example, if I drop my pen and it falls to the ground, I can say it is because there are invisible pieces of elastic pulling it down, or I can say there are invisible fairies in the room that are doing it. And that approach leads nowhere.

It is explained quite well here:

I think you're putting a skeptics spin on the interpretation.

Occams Razor doesn't distinguish between physical and non physical entities, nor does it distinguish between what is right and what is wrong, or what is correct and what is incorrect.
It makes no such qualitative statements, which is part of the problem when interpreting this tool.

 

[Some Friggin Guy]

Anyway, you have my permission to smack upside the head anyone claiming the Ockham's Razor proves anything.

Wouldn't you be able to use Ockham's razor to prove that Ockham shaved at least once in his life?

Sorry, I'm tired and couldn't resist.

 

[RichardR]

I think you're putting a skeptics spin on the interpretation.

Occams Razor doesn't distinguish between physical and non physical entities, nor does it distinguish between what is right and what is wrong, or what is correct and what is incorrect.
It makes no such qualitative statements, which is part of the problem when interpreting this tool.

I never said it did any of those things.

 

[Pyrian]

Some Friggin Guy:

Anyway, you have my permission to smack upside the head anyone claiming the Ockham's Razor proves anything.

Wouldn't you be able to use Ockham's razor to prove that Ockham shaved at least once in his life?

*smack*

 

[Yahzi]

Here is a good example of Occam's Razor:

"Where does lightening come from?"

One could say Zeus does it, or it is caused by natural processes.

That's not a good example. Todd gave a better example. To convert your example into a good one:

"One could say that electrons flow from the ground to the air, or one could say that Zeus causes electrons to flow from the ground to the air."

Occam's Razor proves stuff just fine. It is, in fact, the only proof you have that Santa Claus does not exist. Since absolutely everyone here agress that Santa Claus does not exist (and also elves, pixies, leprechauns, unicorns, dragons, compassionite conservatives, etc.), we must conclude that the Razor is in fact compelling in every single instance it is used - except God.

As usual, God gets a special exemption. No one objects when the Razor is used to disprove any of the infinite imaginary creatures made up by delusional lunatics and poets: only when God is subject to the Razor do people suddenly decide that it is somehow inadequate.

This special exemption says a lot about the notion of God, but nothing at all about Occam's Razor.

 

[Yahzi]

The razor while useful is just a tool, not all tools work in all situations.

The Razor is a fundamental principle of reason, right up there with the three basic laws of logic and the assumption that the world is law-governed.

Everyone uses the Razor every single time they frame any argument. Everyone assumes its absolute power, utility, and correctness every time they offer any explanation of anything.

It is far more than just a tool, and it is applied in every single argument ever advanced.

If it were not, I could legitimately disprove every explanation by offering an alternate explanation that was exactly the same as the first one, but had an invisible, intangible elf. Unless you are prepared to treat every explanation offered, of every phenomona imaginable, equally with the invisible elf explanation, then you are endorsing the Razor. And if you are prepared to do so, you are far to insane to have any logical conversation with. Hence we see that the Razor applies to everything except insane people.

 

[csense]

Occam's Razor is not a principle, and it specifically is not a principle of contradiction. As previously stated, it's use is limited to matters theoretical.
It is used to refine a given theory, or theories which are more similar, than they are dissimilar, so If anything, one can say it concerns itself more with identity.

Simplicity, or (the law of) Parsimony demands certain assumptions be made for it to be of any value whatsoever, and these assumptions are quite subjective.

Either way, to say that either of these two prove anything, is poor reasoning.