Occam's Razor

This is carried over from this thread. I think this worth further discussion but did not want to take over the other thread.

Occam’s razor does not state “the simplest answer is most likely to be the correct one” although this is a popular (mis)translation of it. If this is what was stated, then it would be a proposition and therfore could have a truth value and could be refuted as has been claimed (although I’m still unclear how it would be self refuting even if it were a proposition).

Occam’s Razor is an imperitive, “Do not mulitply beyond necessity”. Imperitives are not propositions, they can have no truth value, so they cannot be refuted (as something must be false if it is refuted). They can be denied (“No, I want to multiply by 100x more than necessary”) but this is not the same as refuting, it is simply not going along with them.

Further more, it is impossible to have good reason to refuse to go along with Occam’s Razor. Why? The key words are “beyond necessity”. Most people take Occam’s Razor to merely be stating that the simple answers are correct ones. This is not true - this would be to drastically misuse this principle (something commonly done, as I stated in the previous thread). If you have some good cause not to choose the simplest answer, then Occam’s Razor does not apply to the situation - because you are multiplying as is necessary to fit the facts, not adding unneccessary articulations.

Take, for instance, Ptolomeic astronomy, a field of science often criticised for it’s ludicrous complexity. The orbit of the planets was posited to consist of two circles. Firstly, the planets would orbit around the earth in a circular motion. Then, there would be an epicycle on that orbit, so it orbited around the simple circular orbit as well. Often these epicycles, which seem absurd to modern observers, are said to be violating Occam’s Razor because they are an excessive multiplication.

This is not the case, however, as they were required to explain the movement of the planets. As the planets move at different speeds, and the earth is also orbiting and not stationary as they thought, the planets will overtake eachother, which make it appear like they are moving back on themselves in the sky. Thus the epicycles were needed to explain their movement - they did not multiply beyond necessity.

One final point. Occam’s razor ensures that you do not make assertions to which you have to cause to state, as I hope I have shown. This does not mean that your assertions are true. Indeed what you take to be beyond necessity is logically indeterminable - there is not way you can say for sure which factor is beyond necessity (the ptolomeics would say that the idea of an earth which moves is beyond necessity - it would have been thought a self-contradictory statement). What Occam’s Razor ensures is that you are JUSTIFIED. If you do multiply beyond necessity, you are making a claim which is unjustified. If you stick to the facts as you know them, and posit the minimum that is needed in order for those facts to all fit together, then it will be almost, if not totally, impossible for anyone to claim that you were unjustified in your statement, although still perfectly possible that you were wrong. This is why Occam’s Razor cannot genuinely be said to be refuting - such a statement doesn’t actually mean anything at all.

Good post. I’d like to echo similar sentiments, but from a slightly different perspective.

So here’s an example of Occam’s Razor. A man goes around observing crows all day, finding every one he sees to be black. At the end of the day, he announces that he is now very confident that unicorns exist, because all day he has found nothing but confirming evidence for his proposition that “all crows are black and unicorns exist”.

A scientist corrects him, and says, "since your evidence is equally consistent with the proposition “all crows are black”, to assert that it is also evidence for your extended proposition violates Occam’s Razor.

In other words, Occam’s Razor is a minimalist imperative regarding empiricism. If we make observations and use those observations as support for asserted physical laws, the laws that they support should be MINIMAL - they shouldn’t assert one iota more than that for which they have direct evidence.

(This given an excellent reason to be non-theist, by the way – and is the prime reason why religion and science are not logically compatible in a fundamental sense.)

However, “nature does not multiply beyond necessity”, would be a proposition, no?

yeah… whats your point? I fail to see how that bears relation to a discussion of Occam’s Razor.

It IS a proposition (one not stated by Occam’s Razor) but one which I see justification of as impossible to come by (it would require a direct view of nature, in which case we don’t need any tools of reasoning - we’ve already seen it all).

Wouldn’t this violate the views of most roman catholic parents? :wink:


But yeah. In my experience I usually regret bringing up Occam’s Razor in a discussion against say creationism because my opponent 9 times out of 10 thinks it means something like “The easiest assertion to explain is the right one.” This is entirely not the case. The assertion that requires the least assumptions to justify it tends to be the right one. Evolution does not assume a whole lot if anything. Science accounts for observations witnessed in the field and in the lab and draws extrapolations from data. Religion tells stories.

Extrapolations are not assumptions. [-X

Creationists make very big assumptions with their claim. Either that A) a god exists, B) we were “designed”, or C) everything is here for a reason. A) You’ve assumed that there is a god, B) if we were “designed” how come we have so many flaws and superfluous attributes, and C) you’ve assumed that there is a such thing as “fate/reason”. Evolutionists simply state the facts and say whats going on and what has happened. Oh, and they use tangible evidence to support their claims.

What do people think of this statement below in relation to the Razor?

My expiriences triumphs over reason in my being and ultimately it is my expiriences that defines me instead of reason.

Accurate enough.

In which case ‘all crows are black’ violates Occam’s Razor, so you’ve contradicted and destroyed your own example and about 95% of science.

No it doesn’t. It doesn’t follow from ‘all crows are black’ that ‘there is no God’. Indeed, the proof or absence thereof for black crows says absolutely nothing about the existence of God, or Unicorns.

Indeed, your claim that this is an excellent reason to be a non-theist violates Occam’s Razor as you have no direct proof (in the example or explanation offered) of the non-existence of God.

You see, from a contradictory, self-refuting principle we get contradictory, self-refuting arguments. Sorry, but what you’ve written here is, logically, nonsense. Science and religion logically compatible because they both frequently violate Occam’s Razor. I advise you to put down the Dawkins and start paying attention to people who’ve got a clue.

I think that statement is sharp… (as well as true- reason could be a mental experience afterall)

welcome to the boards

-Imp