Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 120 (8763 total)
Current session began: 
Page Loaded: 06-23-2017 6:23 AM
377 online now:
Astrophile, CRR, Faith, PaulK, Phat (AdminPhat), Tangle (6 members, 371 visitors)
Chatting now:  Chat room empty
Newest Member: aristotle
Post Volume:
Total: 811,885 Year: 16,491/21,208 Month: 2,380/3,593 Week: 493/882 Day: 11/103 Hour: 2/4

Announcements: Reporting debate problems OR discussing moderation actions/inactions


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
1
2345678Next
Author Topic:   Abductive Reasoning In Science
Straggler
Member
Posts: 10196
From: London England
Joined: 09-30-2006


Message 1 of 120 (672177)
09-04-2012 1:33 PM


In this thread I want to get to grips with abduction and it's role in science. Here from the wiki page on Abductive Reasoning is a brief synopsis of what abduction entails in comparison to the more familiar inductive and deductive methods of reasoning:

Wiki writes:

Deduction allows deriving b from a only where b is a formal consequence of a. In other words, deduction is the process of deriving the consequences of what is assumed. Given the truth of the assumptions, a valid deduction guarantees the truth of the conclusion. For example, given that all bachelors are unmarried males, and given that this person is a bachelor, it can be deduced that this person is an unmarried male.

Induction allows inferring b from a, where b does not follow necessarily from a. a might give us very good reason to accept b, but it does not ensure b. For example, if all of the swans that we have observed so far are white, we may induce that the possibility that all swans are white is reasonable. We have good reason to believe the conclusion from the premise, but the truth of the conclusion is not guaranteed. (Indeed, it turns out that some swans are black.)

Abduction allows inferring a as an explanation of b. Because of this, abduction allows the precondition a to be abduced from the consequence b. Deduction and abduction thus differ in the direction in which a rule like "a entails b" is used for inference. As such abduction is formally equivalent to the logical fallacy affirming the consequent or Post hoc ergo propter hoc, because there are multiple possible explanations for b. For example, after glancing up and seeing the eight ball moving towards us we may abduce that it was struck by the cue ball. The cue ball's strike would account for the eight ball's movement. It serves as a hypothesis that explains our observation. There are in fact infinitely many possible explanations for the eight ball's movement, and so our abduction does not leave us certain that the cue ball did in fact strike the eight ball, but our abduction is still useful and can serve to orient us in our surroundings. This process of abduction is an instance of the scientific method. There are infinite possible explanations for any of the physical processes we observe, but we are inclined to abduce a single explanation (or a few explanations) for them in the hope that we can better orient ourselves in our surroundings and eliminate some of the possibilities.

In this thread I want to ask:

1) How widely is abductive reasoning used in science?
2) Is abductive reasoning a valid tool for science to use in formulating theories?
3) What are some key examples of abductive reasoning relevant to the sort of science topics regularly covered at EvC (Evolution, Big Bang, Age of earth etc. etc. etc.)?
4) Can we 'do science' without abductive reasoning? Or is it a vital component of the scientific method?


Replies to this message:
 Message 3 by RAZD, posted 09-04-2012 3:26 PM Straggler has responded
 Message 8 by Dr Adequate, posted 09-04-2012 6:03 PM Straggler has responded
 Message 14 by crashfrog, posted 09-06-2012 12:36 PM Straggler has responded
 Message 25 by Dr Jack, posted 09-06-2012 6:42 PM Straggler has not yet responded

  
Admin
Director
Posts: 12516
From: EvC Forum
Joined: 06-14-2002
Member Rating: 3.2


Message 2 of 120 (672179)
09-04-2012 1:49 PM


Thread Copied from Proposed New Topics Forum
Thread copied here from the Abductive Reasoning In Science thread in the Proposed New Topics forum.
    
RAZD
Member
Posts: 18650
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.8


Message 3 of 120 (672184)
09-04-2012 3:26 PM
Reply to: Message 1 by Straggler
09-04-2012 1:33 PM


hypothesis
Hi Straggler,

2) Is abductive reasoning a valid tool for science to use in formulating theories?

It's a valid way to get an hypothesis, and to develop tests that you could do to formalize it into theory.

I don't see it being much different from conjecture.

3) What are some key examples of abductive reasoning relevant to the sort of science topics regularly covered at EvC (Evolution, Big Bang, Age of earth etc. etc. etc.)?

Curiously, I thought evolution was developed from deductive reasoning from examples where it is known to occur (likewise the original Theory of Natural Selection), am I wrong?

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 1 by Straggler, posted 09-04-2012 1:33 PM Straggler has responded

Replies to this message:
 Message 4 by Straggler, posted 09-04-2012 4:53 PM RAZD has responded
 Message 41 by Straggler, posted 09-07-2012 12:29 PM RAZD has acknowledged this reply
 Message 47 by Dr Adequate, posted 09-07-2012 5:11 PM RAZD has acknowledged this reply

  
Straggler
Member
Posts: 10196
From: London England
Joined: 09-30-2006


Message 4 of 120 (672192)
09-04-2012 4:53 PM
Reply to: Message 3 by RAZD
09-04-2012 3:26 PM


Re: hypothesis
RAZD writes:

It's a valid way to get an hypothesis, and to develop tests that you could do to formalize it into theory.

This is where the verifiable/falsifiable predictions of a theory come in.

RAZD writes:

Curiously, I thought evolution was developed from deductive reasoning from examples where it is known to occur (likewise the original Theory of Natural Selection), am I wrong?

I think you are wrong. I think the theory of common ancestry was developed from the available evidence by means of a combination of deductive, inductive and abductive reasoning. I would suggest this is true of most scientific theories.

Can you explain how the theory that ALL life on Earth, including as yet undiscovered species, shares a common ancestor can be derived purely by a process of deductive logic?


This message is a reply to:
 Message 3 by RAZD, posted 09-04-2012 3:26 PM RAZD has responded

Replies to this message:
 Message 5 by RAZD, posted 09-04-2012 5:09 PM Straggler has responded

  
RAZD
Member
Posts: 18650
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.8


Message 5 of 120 (672194)
09-04-2012 5:09 PM
Reply to: Message 4 by Straggler
09-04-2012 4:53 PM


Re: hypothesis
Hi Straggler,

This is where the verifiable/falsifiable predictions of a theory come in.

I think you might be jumping the gun to theory (unless I read you wrong). I did a quick google on scientific method theory and got these top picks:

http://chemistry.about.com/od/chemistry101/a/lawtheory.htm

quote:
Hypothesis

A hypothesis is an educated guess, based on observation. Usually, a hypothesis can be supported or refuted through experimentation or more observation. A hypothesis can be disproven, but not proven to be true.

Theory

A scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing. A theory is valid as long as there is no evidence to dispute it. Therefore, theories can be disproven. Basically, if evidence accumulates to support a hypothesis, then the hypothesis can become accepted as a good explanation of a phenomenon. One definition of a theory is to say it's an accepted hypothesis.

Law

A law generalizes a body of observations. At the time it is made, no exceptions have been found to a law. Scientific laws explain things, but they do not describe them. One way to tell a law and a theory apart is to ask if the description gives you a means to explain 'why'.


and http://wilstar.com/theories.htm

quote:
Scientific Law: This is a statement of fact meant to describe, in concise terms, an action or set of actions. It is generally accepted to be true and universal, and can sometimes be expressed in terms of a single mathematical equation. Scientific laws are similar to mathematical postulates. They dont really need any complex external proofs; they are accepted at face value based upon the fact that they have always been observed to be true.

Hypothesis: This is an educated guess based upon observation. It is a rational explanation of a single event or phenomenon based upon what is observed, but which has not been proved. Most hypotheses can be supported or refuted by experimentation or continued observation.

Theory: A theory is what one or more hypotheses become once they have been verified and accepted to be true. A theory is an explanation of a set of related observations or events based upon tested hypotheses and verified multiple times by detached groups of researchers. Unfortunately, even some scientists often use the term "theory" in a more colloquial sense, when they really mean to say "hypothesis." That makes its true meaning in science even more confusing to the general public.


Now a logical conclusion - by whatever method - to me qualifies as an educated guess or conjecture.

This to me says that some verification needs to be done, and that it should have some independent verification, to become theory.

Enjoy


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 4 by Straggler, posted 09-04-2012 4:53 PM Straggler has responded

Replies to this message:
 Message 6 by Straggler, posted 09-04-2012 5:30 PM RAZD has responded

  
Straggler
Member
Posts: 10196
From: London England
Joined: 09-30-2006


Message 6 of 120 (672200)
09-04-2012 5:30 PM
Reply to: Message 5 by RAZD
09-04-2012 5:09 PM


Re: hypothesis
RAZD writes:

I think you might be jumping the gun to theory (unless I read you wrong).

I am not suggesting that anything be described as a theory until the predictions (i.e. logical consequences deductively derived) have been tested to a reasonable degree.

For example we might abductively reason that some newly discovered species is part of the same tree of life as all other known life on Earth rather than something created ex-nihilo by magic (or whatever).

From this we would predict (using deductive reasoning) that the new species must share genetic make-up with other species on Earth. We can test this prediction through genetic analysis of the new species. Verification of this prediction doesn't disprove unfalsifiable notions of ex-nihilo creation. But it does allow us to confidently (albeit tentatively) discard such notions in favour of common descent. Right?

RAZD writes:

Now a logical conclusion - by whatever method - to me qualifies as an educated guess or conjecture.

Logic alone without testing by verifiable prediction - Sure.

But you have stated that the theory of evolution can be derived purely deductively (i.e. without either inductive or abductive reasoning components) have you not?

Question: Can you explain how the theory that ALL life on Earth, including as yet undiscovered species, shares a common ancestor can be derived purely by a process of deductive logic?


This message is a reply to:
 Message 5 by RAZD, posted 09-04-2012 5:09 PM RAZD has responded

Replies to this message:
 Message 7 by RAZD, posted 09-04-2012 6:01 PM Straggler has responded
 Message 11 by Jon, posted 09-04-2012 6:35 PM Straggler has not yet responded

  
RAZD
Member
Posts: 18650
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.8


Message 7 of 120 (672208)
09-04-2012 6:01 PM
Reply to: Message 6 by Straggler
09-04-2012 5:30 PM


Re: hypothesis
Hi Straggler,

Then we are in agreement, and I was reading more into your previous reply than was intended. My bad.

But you have stated that the theory of evolution can be derived purely deductively (i.e. without either inductive or abductive reasoning components) have you not?

Not really, just the initial hypothesis formation.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 6 by Straggler, posted 09-04-2012 5:30 PM Straggler has responded

Replies to this message:
 Message 10 by Straggler, posted 09-04-2012 6:29 PM RAZD has responded

  
Dr Adequate
Member
Posts: 15934
Joined: 07-20-2006
Member Rating: 3.4


(1)
Message 8 of 120 (672210)
09-04-2012 6:03 PM
Reply to: Message 1 by Straggler
09-04-2012 1:33 PM


1) How widely is abductive reasoning used in science?
4) Can we 'do science' without abductive reasoning? Or is it a vital component of the scientific method?

Very widely, no, and yes, respectively.

Consider that we are performing abduction when we reason from "The litmus paper is this color" to "this solution is acidic" or from "the thermometer gives this reading" to "this liquid is hot".

2) Is abductive reasoning a valid tool for science to use in formulating theories?

That depends what you mean by theory. It does not allow us to produce grand general theories, but only theories in the sense of an explanation for a particular thing.

Why? Because abduction is only possible in the context of a theory. Suppose we have a patient with measles? What do we abduce? That depends on whether our theory of the causes of disease involves germs or witches.

3) What are some key examples of abductive reasoning relevant to the sort of science topics regularly covered at EvC (Evolution, Big Bang, Age of earth etc. etc. etc.)?

Well, the Big Bang can be abduced from the evidence plus the theory of relativity; it can then be made hypothetico-deductive, we reason forward from it to what we should see. Similarly with the age of the earth, we can abduce it from various physical and geological theories, we can then reason forward from it.

Evolution is interesting because nearly every datum wears two faces. Take intermediate forms, for example. We can reason forward from Darwinism to the existence of intermediate forms (a morphological judgement) and take their existence (and lots of other stuff too, obviously) as confirmation of the theory. But then in the light of the theory (once we have been convinced of it by this and other lines of evidence) we can interpret them as being transitional species, which is a historical judgement.

Again, consider chromosome 2. From our theory plus the fact that humans have one fewer chromosome than the other apes, we can deduce some things about what the human chromosome should look like and see if it does. The fact that we're right tends to confirm our theory. This is hypothetico-deductive reasoning. But once we have been convinced of the theory by this and other lines of evidence, we can abduce in the light of the theory that a chromosome fusion took place.

Being too stupid to understand the difference between these two modes of reasoning is of course part of the creationists' stock in trade.


This message is a reply to:
 Message 1 by Straggler, posted 09-04-2012 1:33 PM Straggler has responded

Replies to this message:
 Message 9 by Straggler, posted 09-04-2012 6:18 PM Dr Adequate has responded

  
Straggler
Member
Posts: 10196
From: London England
Joined: 09-30-2006


Message 9 of 120 (672213)
09-04-2012 6:18 PM
Reply to: Message 8 by Dr Adequate
09-04-2012 6:03 PM


Good post.

Dr A writes:

Being too stupid to understand the difference between these two modes of reasoning is of course part of the creationists' stock in trade.

I don't think it is limited to creationists. I think rampant demands for the disproof of things designed to be disprovable and relentless accusations of "illogical arguments" whenever non-deductive modes of reasoning are applied to the origins of various unfalsifiable concepts show that the confusion is rife in even those who should know better......


This message is a reply to:
 Message 8 by Dr Adequate, posted 09-04-2012 6:03 PM Dr Adequate has responded

Replies to this message:
 Message 12 by Dr Adequate, posted 09-04-2012 7:04 PM Straggler has responded

  
Straggler
Member
Posts: 10196
From: London England
Joined: 09-30-2006


(1)
Message 10 of 120 (672215)
09-04-2012 6:29 PM
Reply to: Message 7 by RAZD
09-04-2012 6:01 PM


Re: hypothesis
Straggler writes:

But you have stated that the theory of evolution can be derived purely deductively (i.e. without either inductive or abductive reasoning components) have you not?

RAZD writes:

Not really, just the initial hypothesis formation

Well I think you are still wrong. I think you are misunderstanding or under-estimating the role of abductive (and inductive) reasoning in the formation of scientific theories and hypotheses.

Can you explain how the hypothesis that ALL life on Earth, including as yet undiscovered species, shares a common ancestor can be derived purely by a process of deductive logic from the available evidence?

As I understand it deductive logic cannot go from the specific to the general. So I am intrigued as to how you think any theory/hypothesis involving a generalised statement can be deductively derived from specific observable instances.

I also think this misunderstanding on your part of the way scientific theories and hypotheses are developed lies at the heart of most of our disagreements........


This message is a reply to:
 Message 7 by RAZD, posted 09-04-2012 6:01 PM RAZD has responded

Replies to this message:
 Message 42 by RAZD, posted 09-07-2012 1:47 PM Straggler has responded

  
Jon
Inactive Member


Message 11 of 120 (672217)
09-04-2012 6:35 PM
Reply to: Message 6 by Straggler
09-04-2012 5:30 PM


Re: hypothesis
editing...

Edited by Jon, : No reason given.


Love your enemies!

This message is a reply to:
 Message 6 by Straggler, posted 09-04-2012 5:30 PM Straggler has not yet responded

  
Dr Adequate
Member
Posts: 15934
Joined: 07-20-2006
Member Rating: 3.4


(3)
Message 12 of 120 (672220)
09-04-2012 7:04 PM
Reply to: Message 9 by Straggler
09-04-2012 6:18 PM


I don't think it is limited to creationists. I think rampant demands for the disproof of things designed to be disprovable and relentless accusations of "illogical arguments" whenever non-deductive modes of reasoning are applied to the origins of various unfalsifiable concepts show that the confusion is rife in even those who should know better......

Well what I mean is that (for example) creationists will complain that scientists assume that species are transitional, based on their theory.

Now, this isn't how it works. Scientists see that forms are intermediate. They conclude (from this and other evidence) that the theory is correct, since this is one of the things that it predicts. They they abduce that when they are looking at intermediate forms, they are looking at transitional species.

The creationist, naturally gifted with stupidity and determined to misunderstand everything you tell him, conflates seeing that the forms are intermediate with abducing that the species are transitional.

Again, consider the argument from morphology. The creationist pretends that scientists assume that similarity indicates relatedness rather than a common designer.

What actually happens? The theory predicts that we should be able to robustly classify organisms by means of a tree-like structure. We look, and we can. This tends to confirm our theory. Once we have been convinced by this and other lines of evidence that the theory is correct, we then abduce from the theory that the tree is in fact a family tree. Again, a sufficiently retarded creationist can conflate the two processes.

---

These examples demonstrate the importance of abduction to evolutionary biology. Roughly speaking, when we compare the predictions of the theory to the evidence found in the present, we are being hypothetico-deductive, but when we reconstruct the past history of evolution from the evidence, we are performing abduction in the light of the theory.

(I say "roughly speaking" because statements about history can be themselves subjected to hypothetico-deductive inquiry. For example, having abduced the relationship of birds to crocodiles from the fossil evidence, we have a prediction about the genetic evidence.)


This message is a reply to:
 Message 9 by Straggler, posted 09-04-2012 6:18 PM Straggler has responded

Replies to this message:
 Message 13 by Straggler, posted 09-06-2012 12:22 PM Dr Adequate has responded

  
Straggler
Member
Posts: 10196
From: London England
Joined: 09-30-2006


Message 13 of 120 (672311)
09-06-2012 12:22 PM
Reply to: Message 12 by Dr Adequate
09-04-2012 7:04 PM


Dr A writes:

Roughly speaking, when we compare the predictions of the theory to the evidence found in the present, we are being hypothetico-deductive, but when we reconstruct the past history of evolution from the evidence, we are performing abduction in the light of the theory.

A common creationist confusion along these lines pertains to dating, the geologic column and fossils. The creationist misunderstanding/complaint is based on thinking that fossils are dated by their position in the geologic column whilst the layers of the geologic column are dated by means of which fossils they contain.

There are instances where the age of something is abduced (is that the correct word) in terms of existing and accepted theory. But that is not how the original ages of these things was determined.


This message is a reply to:
 Message 12 by Dr Adequate, posted 09-04-2012 7:04 PM Dr Adequate has responded

Replies to this message:
 Message 28 by Dr Adequate, posted 09-06-2012 11:21 PM Straggler has not yet responded

  
crashfrog
Inactive Member


Message 14 of 120 (672312)
09-06-2012 12:36 PM
Reply to: Message 1 by Straggler
09-04-2012 1:33 PM


Is abductive reasoning a valid tool for science to use in formulating theories?

I'd like to get at what you mean by "valid." Logically valid?

It's clear simply from the description that abduction is logically fallacious. But it's clear from history and the existence of technology that scientific abduction produces useful, accurate information about the natural world.

I would go so far to suggest that if scientific abduction is illogical, that exposes a problem with logic, not with scientific abduction. Logic has a pretty mixed history of producing accurate knowledge. For instance, Aristotlian physics.

Edited by crashfrog, : No reason given.


This message is a reply to:
 Message 1 by Straggler, posted 09-04-2012 1:33 PM Straggler has responded

Replies to this message:
 Message 15 by Modulous, posted 09-06-2012 1:16 PM crashfrog has responded
 Message 17 by nwr, posted 09-06-2012 1:37 PM crashfrog has responded
 Message 23 by Straggler, posted 09-06-2012 4:03 PM crashfrog has responded
 Message 29 by Dr Adequate, posted 09-06-2012 11:26 PM crashfrog has not yet responded

  
Modulous
Member
Posts: 7407
From: Manchester, UK
Joined: 05-01-2005
Member Rating: 3.1


(2)
Message 15 of 120 (672314)
09-06-2012 1:16 PM
Reply to: Message 14 by crashfrog
09-06-2012 12:36 PM


I would go so far to suggest that if scientific abduction is illogical, that exposes a problem with logic, not with scientific abduction. Logic has a pretty mixed history of producing accurate knowledge. For instance, Aristotlian physics.

Logic is not sufficient to determine everything in nature, but it is, I think, necessary.

Abduction is logical, it is one of the modes of logical reasoning (ie., deductive, inductive and abductive). It is not deductively valid. This isn't a problem with deductive logic - after all, plenty of physics seems to be based on the deductions of mathematics, it just means that deduction does not have a monopoly in reasoning logically.


This message is a reply to:
 Message 14 by crashfrog, posted 09-06-2012 12:36 PM crashfrog has responded

Replies to this message:
 Message 16 by PaulK, posted 09-06-2012 1:25 PM Modulous has acknowledged this reply
 Message 18 by crashfrog, posted 09-06-2012 1:38 PM Modulous has responded

    
1
2345678Next
Newer Topic | Older Topic
Jump to:


Copyright 2001-2015 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2017