Abductive Reasoning In Science

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.

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.)?

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

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?

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

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

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

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?

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?

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.)?

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.

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

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......

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.

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

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.