Ockham's Razor

[Freethinker]

Is Ockham's Razor objective? Is there a definite way to judge simplicity?

Try to actually read my post

Ockham's razor, also spelled "Occam's razor", but also called "law of economy" or "law of parsimony", is a principle stated by William of Ockham, that entities are not to be multiplied beyond necessity (non sunt multiplicanda entia praeter necessitatem).

 

It is NOT "Simplisity" as such. It is number of agents. Let's use an example. The existence of "Nature" (the physical existence we have). let's take two competing theories

 

1) Nature is responsible for Nature

 

2) GOD is responsible for Nature

 

In #1 there is ONE entity Nature itself. In #2 there are TWO entities Nature and GOD.

 

Apply "entities are not to be multiplied beyond necessity".

 

The objective evaluation is simple. If Nature can explain Nature as well as GOD, then OBJECTIVE application of Ockham's Razor shaves GOD away.

[Buffy]

(Whine) Okay, here goes:

 

My Aunt Sylvia takes me to a sushi place for dinner. Why the sushi place?

 

Hypothesis A: We like sushi.

 

Hypothesis B: Aunt Sylvia was stationed on an Army Base in Japan during the Vietnam war and the sushi place is owned by her old boyfriend Kobayashi who comes from a long line of sushi chef's who founded the first sushi school to specialize in the proper training of preparation of fugu, and he gives her a discount because she lent him $20 back in 1971 to get his tire repaired. And she always orders the steak...

 

Occam would say that A is true, while Aunt Sylvia will affirm B.

 

FT will find something he doesn't like about this, but he's the only valid judge, so we'll probably have to come up with lots more examples....

 

Cheers,

Buffy

[Fishteacher73]

I do not think Occam's razor is intended to predict every individual event. It should be applied to generic events that can occur agian and again. The simplest explanation that most people go eat sushi is that they like it. It is more like probability that anything else I feel.

[Buffy]

It is more like probability that anything else I feel.

I think that's what FT is arguing against though, its not a "guide" to guessing, its a law (simplest explanation *has* to be true).

 

The wikipedia entry on this one is pretty enlightening though:

http://en.wikipedia.org/wiki/Occam's_Razor

 

And what I love are the "Anti Razors" mentioned:

 

Walter of Chatton: "If three things are not enough to verify an affirmative proposition about things, a fourth must be added, and so on"

Immanual Kant: "The variety of beings should not rashly be diminished."

Karl Menger: "Entities must not be reduced to the point of inadequacy" and "It is vain to do with fewer what requires more"

 

Cheers,

Buffy

[Fishteacher73]

Probability is not a guide. It can predict the normal outcome if there are enough sample values. It will not predict heads or tails, but it will predict that given a reasonably large set of experiments you will roughly get a probability of 1/2. There is no guide to this. There may be aberrant events in the local observation set, but when taken as a whole, they even out.

 

So I guess I fall in between Buffy and FT. I believe that it works to describe large generic events but allows for some local variation from external causes.

[lindagarrette]

I do not think Occam's razor is intended to predict every individual event. It should be applied to generic events that can occur agian and again. The simplest explanation that most people go eat sushi is that they like it. It is more like probability that anything else I feel.

In nature, the simplest explanation is always the best. We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. Isaac Newton

[Freethinker]

All I am seeing is a lot of misrepresentations which are being claimed as refuting examples.

 

Ockham's Razor is ONLY applicable, as I stated in my post "when you have two competing theories which make exactly the same predictions, the one that is simpler is the better."

 

Again with "simpler" being defined as "fewer agents".

 

So yes Buffy, let's review some of the examples to see if theya re otherwise "equal".

 

Occam would say that A is true, while Aunt Sylvia will affirm B.

This example is NOT "equal competing theories". They are two different POV's, explanations.

 

"A" describes why YOU wanted to go. "B" describes why SHE wanted to go.

 

And this ties into your other post:

Walter of Chatton: "If three things are not enough to verify an affirmative proposition about things, a fourth must be added, and so on"

At no point does Ockham's razor even suggest that one should stop at FEWER than needed. Just not MORE than needed.

Immanual Kant: "The variety of beings should not rashly be diminished."

At no point does Ockham's razor even suggest that one should stop at FEWER than needed. Just not MORE than needed.

Karl Menger: "Entities must not be reduced to the point of inadequacy" and "It is vain to do with fewer what requires more"

At no point does Ockham's razor even suggest that one should stop at FEWER than needed. Just not ... well hopefully you've caught on by now...

[Fishteacher73]

In nature, the simplest explanation is always the best.

 

One must make sure that all the pieces of the puzzle are there. If not, then ID becomes the simplest explanation of life. Yet when other evidence comes to light (Gould's "Panda's Thumb" is a good example) the theory must be re-vamped. (I definatly am not arguing for ID, but just thought that this might make a good example). Just a the sushi example was lacking in evidence, the logical conclusion would be that the aunt liked sushi. Once it came to light that she did not like sushi, another hypothesis must be made. As the information had grown, the second answer became the simplest explanation.

[Buffy]

All I am seeing is a lot of misrepresentations which are being claimed as refuting examples.

Fish: Told ya so! ;)

 

Ockham's Razor is ONLY applicable, as I stated in my post "when you have two competing theories which make exactly the same predictions, the one that is simpler is the better."

 

Again with "simpler" being defined as "fewer agents".

 

So yes Buffy, let's review some of the examples to see if theya re otherwise "equal".

 

This example is NOT "equal competing theories". They are two different POV's, explanations.

 

"A" describes why YOU wanted to go. "B" describes why SHE wanted to go.

Here's the thing: I know I'm a dumb blonde and can only have "a point of view" and not be able to propound a theory, but the two hypotheses are in fact valid competing theories of why Aunt Sylvia goes to the sushi place (not btw, why *I* like to go to the sushi place, but as observed by a third party trying to figure out how the system works), with the proviso that the last line ("...she orders the steak.") should be left off because its data intended to be added after the fact to show that Hypothesis A could be proven false.

 

Now what I think has gotten us all tied up in knots is actually the issue pointed out by this example of *how its used* (although what it means is fun to argue too!). If its intended to be predictive of competing theories when full knowledge of all data does not exist, then the interpretation should be "its the likelyhood that the theory is true" whereas if it is an ex post facto "see, we now know that the theory is right and Occam backs that up," then there's no way to come up with a counter-example like FT is asking for, cuz it actually works!

 

In summary, Occam can be used BOTH ways and you can more explicitly say: "If you don't have all the facts, the simpler explanation is *probably* true, and if you do have all the facts, you'll see that the simplest *is* true."

 

So, we're all right about the completely different issues we're arguing!

 

Cheers,

Buffy

[Buffy]

Oh and there's the third issue of its source, which is indicated by its original name: "Law of Parsimony". Its also intended to eliminate waste and irrelevance, in which case its not really a "law" so much as an admonition to theory-developers to try to get rid of all the extraneous (unneeded) elements of their theory. Just plain good form! I go for that!

 

Cheers,

Buffy

[Freethinker]

One must make sure that all the pieces of the puzzle are there. If not, then ID becomes the simplest explanation of life.

Sorry, wrong. ID INCREASES the complexity of the answer. It does not provide a less complicated answer for existence and it adds the requirement for the explanation of the Designer. It at least doubles the complexity.

[Freethinker]

Fish: Told ya so! ;)

If you were clever enough to predict that I would recognize your error, why not correct it before posting it?

Here's the thing: I know I'm a dumb blonde and can only have "a point of view" and not be able to propound a theory

I don't know if you are blond and from what I have read I would not say dumb. I am concerned that you have such a negative image of yourself. Having even stated before that you dislike yourself.

but the two hypotheses are in fact valid competing theories of why Aunt Sylvia goes to the sushi place (not btw, why *I* like to go to the sushi place, but as observed by a third party trying to figure out how the system works), with the proviso that the last line ("...she orders the steak.") should be left off because its data intended to be added after the fact to show that Hypothesis A could be proven false.

I see, so if we intentionally hide facts in order to mislead, then you can prove me wrong. Interesting approach.

 

They were NOT "equally valid theories". They were not even "theories". They were two statements. One made by an observer and the other by the specific person. But they were STATEMENTS not THEORIES.

If its intended to be predictive of competing theories when full knowledge of all data does not exist,

OK, so let's start adding conditions arbitrarily to make a point. Cute, but no cigar!

[Freethinker]

Oh and there's the third issue of its source, which is indicated by its original name: "Law of Parsimony".

We would have a far more effective discussion if we all actually read what was posted.

 

Show us ANYWHERE that states that Ockham's Razor was ORIGINALLY named the "Law of Parsimony".

Its also intended to eliminate waste and irrelevance, in which case its not really a "law" so much as an admonition to theory-developers to try to get rid of all the extraneous (unneeded) elements of their theory. Just plain good form! I go for that!

But I guess if it gets you to a correct understanding, there is some benefit.

[Buffy]

If you were clever enough to predict that I would recognize your error, why not correct it before posting it?

Course I was arguing that it wasn't an error, so why would I correct it? ;)

I don't know if you are blond and from what I have read I would not say dumb. I am concerned that you have such a negative image of yourself. Having even stated before that you dislike yourself.

Thank you for the complement! Actually people tend to call me vain. I actually like myself a lot, and so does my boyfriend! :D

I see, so if we intentionally hide facts in order to mislead, then you can prove me wrong. Interesting approach.They were NOT "equally valid theories". They were not even "theories". They were two statements. One made by an observer and the other by the specific person. But they were STATEMENTS not THEORIES.

Huh? What was misleading? I wasn't talking about "intentionally" hiding facts. When trying to determine which among a set of proposed theories is correct, it is often the case that there is not enough evidence to make the determination at a given point in time. The only thing I'm proposing here is that one of the ways that Occam's Razor is used--perhaps its vernacular, and therefore might be considered vulgar or apostate--is to make decisions about the correctness of theories where there is not enough data to prove one or the other. This is going on all the time in m-theory land right now!

 

Now as to my example, it was actually chosen partly to make it interesting to the layfolk--of which there are many here (heck I'm layfolk! (albeit with a strong self-image!))--but it appears that the reason that you said the two hypotheses are not equaly valid is that you misunderstood my assumption that it was clear that an independent observer could indeed come up with both hypotheses, and that they were both based on my Aunt Sophie's behavior (not mine, I like sushi! but its not included in this scenario). None of that was clear, so no need to flog you for that: that was my fault for trying to keep it simple. Secondly, as a strict definition of the terms, it would help to have a predictive statement to turn the statement into a theory (whoa, re-read that sentance a few times!). So to be clear, here's a restatement:

 

Initial data point: Observer see's Sophie going to Sushi place

Hypothesis A: Sophie likes Sushi. Prediction A: She'll go into sushi places when hungry.

Hypothesis B: Sophie has a (long involved multi-step explanation of) relationship to the owner of the sushi place, and doesn't like sushi. Prediction A: The only sushi place Sophie would be caught dead in is Kobayashi's.

 

So, next step: The only relevant differences between the two hypotheses is that Hypothesis B contains a set of combined statements that in sum is much more complex than Hypothesis A. Using Occam's razor given only those hypotheses and *with* the intent of choosing between the two without further information (thats a given, not necessarily a "good idea" or in line with the other usage of the razor that I give equal time to), one would choose Hypothesis A. Now upon actually interviewing my Aunt Sophie and finding out that she always ordered steak--a datapoint which was not available to the observer when he decided to choose between the two--it would alter the analysis of the hypotheses to allow a rational decision to indicate that the more complex theory was correct. The point here is that in the absence of all data, it is indeed possible convince one's self that the theory that is actually incorrect is the correct one simply because Occam says to choose the simplest one.

 

Now you can argue that this has nothing to do with the strict definition of Occam's razor and I won't disagree with you on that at all! However as much as many may not like it, it is very common even among physicists to use Occam's Razor as a predictive tool where not all data is available to prove any of the competing theories, even if that process of prediction should be given a different name, which it hasn't as far as I know. Like I say, all these really smart people use it this way while invoking Occam. One more example to throw out: back in the 20's when there was no data to prove any of it, I'm sure a lot of people looked at Quantum Mechanical theory and said "no way is that true! Its so complex it MUST violate Occam's Razor!"

 

As a debater, I'll give you oodles of points for restating my willingness to grant other positions as bad self-image and prevarication. Don't worry, I don't take any of it personally! I'd LOVE to see you go up against Bill O'Reilly!

 

Cheers,

Buffy

[Buffy]

Show us ANYWHERE that states that Ockham's Razor was ORIGINALLY named the "Law of Parsimony".

Ohmigod! FT is absolutely right, here's what it says on the first line of the page from wikipedia I cited earlier:

Ockham's Razor...is a principle attributed to the 14th century English logician and Franciscan friar, William of Ockham that forms the basis of methodological reductionism, also called the

principle of parsimony

.

I apologize profusely for my horrendous faux pas of translating "principle" into "law," as we all *know* that there is no similarity whatsoever between those words. That was clearly intentionally misleading of me. ;) :D :D

 

Cheers,

Buffy

[Thelonious]

Show us ANYWHERE that states that Ockham's Razor was ORIGINALLY named the "Law of Parsimony".

 

www.dictionary.com

 

Actually, it is quite commonly referred to as the Law of Parsimony.

[lindagarrette]

One must make sure that all the pieces of the puzzle are there. If not, then ID becomes the simplest explanation of life. Yet when other evidence comes to light (Gould's "Panda's Thumb" is a good example) the theory must be re-vamped. (I definatly am not arguing for ID, but just thought that this might make a good example). Just a the sushi example was lacking in evidence, the logical conclusion would be that the aunt liked sushi. Once it came to light that she did not like sushi, another hypothesis must be made. As the information had grown, the second answer became the simplest explanation.

Newton was referring to nature (science), not opinion or speculation.