Induction and Science

You lay it out, of course Jon

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Check out Apollo's Temple!

Deleted by JonEdited by Jon, : Deleted

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Check out Apollo's Temple!

I'm going to call this "the Straggler gallop". It's a variant of the Gish Gallop. The procedure seems to be to throw out a bunch of not very relevant questions, demand answers, but otherwise completely avoid engaging in any thoughtful discussion.

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Jesus was a liberal hippie

Hi, nwr. I don't see how this could be anything but a semantic argument.Straggler used the phrase, "consistency of natural laws."In this, I think he was being somewhat redundant: surely it's the consistency of a given natural phenomenon that makes him decide to call it a "law," right? This is the connotation of the phrase "natural law," after all.So, why are you arguing that there are no "natural laws"?Are you arguing that there are actually no natural phenomena that are consistent enough to be considered "laws"? I'd have to disagree with you on that: gravity is a great example of a phenomenon that is consistent enough to merit the designation of "law."So, now I ask, if I can persuade Straggler to reword his statement thus---

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The entirety of science and it's ability to predict is based on the consistency of natural phenomena."

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---would anything substantive about his argument be changed?I don't see how it could.So, either you are objecting to word choice, or you are arguing that no natural phenomena show the consistency that Straggler was claiming.I don't see how either one of these options is a particularly good argument.Edited by Bluejay, : It's patently stupid to use a subtitle that is identical to the thread title. Moose would have a fit.

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Indeed. And if you say it is true that it is not certain, but probably true that gravity will be functioning next week, that your chair will exert an 'opposite force' to keep you falling on your ass, and that your car won't accelerate to light speed when you press the accelerator - then you are making an induction.When you say

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I would call that "statistical reasoning" rather than "inductive logic."

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I have already agree that we use statistical reasoning

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you are saying that you accept induction. This article on inductive logic is almost entirely composed of statistical reasoning. It is very concerned with how confident we can be of our inductions using statistical reasoning.

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An inductive logic is a system of reasoning that extends deductive logic to less-than-certain inferences. In a valid deductive argument the premises logically entail the conclusion, where such entailment means that the truth of the premises provides a guarantee of the truth of the conclusion. Similarly, in a good inductive argument the premises should provide some degree of support for the conclusion, where such support means that the truth of the premises indicates with some degree of strength that the conclusion is true. Presumably, if the logic of good inductive arguments is to be of any real value, the measure of support it articulates should meet the following condition:

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Criterion of Adequacy (CoA):
As evidence accumulates, the degree to which the collection of true evidence statements comes to support a hypothesis, as measured by the logic, should tend to indicate that false hypotheses are probably false and that true hypotheses are probably true.

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{Several sections later...}

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The versions of Bayes' Theorem provided by Equations 9-11 show that for probabilistic inductive logic the influence of empirical evidence on posterior probabilities of hypotheses is completely captured by the ratios of likelihoods, P[en | hjbcn] / P[en | hibcn]. The evidence (cnen) influences the posterior probabilities in no other way. So, the following Law is a consequence of the inductive logic of support functions.

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General Law of Likelihood:
Given any pair of incompatible hypotheses hi and hj, whenever the likelihoods Pα[en | hjbcn] and Pα[en | hibcn] are defined, the evidence (cnen) supports hi over hj, given b, if and only if Pα[en | hibcn] > Pα[en | hjbcn]. The ratio of likelihoods Pα[en | hibcn] / Pα[en | hjbcn] measures the strength of the evidence for hi over hj given b.

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Two features of this law require some explanation. As stated, the General Law of Likelihood does not presuppose that likelihoods of form Pα[en | hjbcn] and Pα[en | hibcn] are always defined. This qualification is introduced to accommodate a conception of evidential support called Likelihoodism, which is especially influential among statisticians. Also, the likelihoods in the law are expressed with the subscript α attached to indicate that the law holds for each inductive support function Pα, even when the values of the likelihoods are not objective or agreed on by all agents in a given scientific community.

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emphasis in original (definitions of most of the symbols are laid out in unquoted reams of text - making it difficult to quote)Edited by Modulous, : No reason given.

What do you take "natural law" to mean?Aristotle had an account of gravity.
Newton had an account of gravity.
Einstein had an account of gravity.Those three all disagreed with one another. Which of them, if any, was a natural law? What does it mean to say that a natural phenomenon is consistent? What would it mean for a natural phenomenon to not be consistent and is that even possible? I'm not sure what argument we are talking about. I seem to recall that Straggler made a bare assertion, but gave no argument. I don't think I am actually doing either of those. But it does come down to the meaning of "natural law". I have heard someone suggest that "natural law" just refers to the phenomenon (or phenemona). And if that's what it means, then I certainly agree that there are natural phenomena.However, most people seem to use "natural law" to refer to the scientific statements that I quite happily call "scientific laws." And if that is what "natural law" means, then I am denying that those laws are part of nature. The fact that there have been several contradictory versions of gravitation laws would tend to support my view.

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Jesus was a liberal hippie

But that is not what I said. I expressed an opinion, but only after considerable badgering. Moreover, I also said that it was a guess. There was no truth claim there. There would be no induction at all in the "opposite force" part.You seem to be losing track. The issue was whether science depends on induction, not whether I can be said to be using it in my private life. According to Rudolph Carnap, the degree to which scientific statements such as Newton's laws are supported by inductive evidence is precisely zero. Do you have a reference that shows otherwise?

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Jesus was a liberal hippie

A quick additional comment here. I posted my first reply just as the board seemed to be going down, so I missed adding this.I would like to thank Blue Jay for actually sticking to the issue, instead of going on a diversion as others (particularly Straggler) have done.

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if a physicist states a new law or a new theory as a system of laws on the basis of experimental he has found, he makes an inductive inference. So does a scientist who assumes an unknown single fact on the basis of known facts; for example, the meteorologist who predicts the weather for tomorrow, the physicist who assumes a certain distribution of the velocities of gas molecules which he cannot directly observe

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When I was talking about induction, I was talking about the above. Are you saying the above is wrong? Do you think the above doesn't happen? Would you be fine calling it schminduction and accepting that scientists do it?

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The statistical concept, for which a very elaborate mathematical theory exists, and which has been fruitfully applied in many fields in science and industry, need not at all be abandoned in order to make room for the inductive concept

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I'm just arguing that the more modern view that has emerged in which the statistical and the inductive have been merged.

Aren't calculations the main difference between inductive logic and statistical reasoning?
Inductive logic doesn't have calculations: it just says "It happened all last year: it will probably happen next year too".
Whereas statistical reasoning calculates the 'odds' of something happening: "There is a 90% chance that it will happen next year".Edited by Panda, : posyt

No - I don't think so: Stastical reasoning can be used to make inductive inferrences and can be used to justify the confidence levels of our inductions. See the article I linke to in Message 76:

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This article will primarily focus on the kind of the approach to inductive logic most widely studied by philosophers and logicians in recent years. These logics apply classical probability theory to sentences to represent a measure of the degree to which evidence statements support hypotheses. This kind of approach usually draws on Bayes' theorem, which is a theorem of probability theory, to articulate how the implications of hypotheses about evidence claims redound to the credit or discredit of the hypotheses. We will examine the extent to which this kind of logic may pass muster as an adequate logic of evidential support, especially in regard to the testing of scientific hypotheses. In particular, we see how such a logic may be shown to satisfy the Criterion of Adequacy

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I think I screwed up my previous post - my head cold is fugging my finking.
I'll try again...*cough*Aren't calculated 'odds' the main difference between Inductive Logic and Statistical Reasoning?
Inductive Logic doesn't require calculated values in it's conclusion: it can just say "It happened all last year: it will probably happen next year too".
Whereas Statistical Reasoning does require the chance of something happening to be calculated and stated: "There is a 90.1% chance that it will happen next year".I would therefore describe Statistical Reasoning as a 'subset' of Inductive Logic.Edited by Panda, : tpyos

The fact you do not like a question and cannot answer it does not make it a bad question. Nor does it make it "off-topic".I would say that we can consider it exceptionally probable that gravity will still be operating as currently experienced and that this conclusion is derived from inductive reasoning. Hence the relevancy.You deny the validity of inductive reasoning and instead have advocated something you are calling "statistical reasoning". So I asked:What is "statistical reasoning"?
How does it work?
In what way is it significantly different to the sort of inductive reasoning that we are all familiar with?And can you specifically describe how can it be used to derive the conclusion that gravity will "probably" still be operating as currently experienced?If you don't like gravity for some reason then apply the same question to friction or the electrostatic force or indeed anything else that is commonly referred to as a "natural law".But ALL I ask is that your don't do your usual trick of posting stock phrases and meaningless philosopho-sounding but unexplained terms as answers. For once in your nut nibbling squirrel brained EvC existence don't hide behind the cover of ambiguity.

Fine by me. Well for example if gravity were to suddenly start randomly swapping between being an attractive force and a repulsive one.Or if friction were to sometimes amplify rather than oppose the motion between two objects with no pattern as to when it would do which.Is it possible for these things to occur - I would say probably not but I would also say that conclusion was derived inductively. Which is why I think it is pertinent to ask how Nwr comes to these same conclusions without using induction.If you can explain his position then I would be delighted to hear it.

So what, according to your view of science, is the scientific conclusion regarding gravity operating as we currently observe it this time next week?Is it not obvious that in a thread about science as non-indictive that this, rather than your opinion, is what I am asking?Edited by Straggler, : No reason given.