Freethought & Rationalism Archive

Detached9 · 01-03-2002, 03:05 PM

I was reading a book that is basically a dialogue between a christian and an atheist. The atheist admits that he thought natural selection sounded circular. The christian of course agrees and then they move on and consider the argument for natural selection being circular to not be required. Did I miss something?

Darwin's Finch · 01-03-2002, 03:11 PM

I assume you are referring to the old saw that natural selection is tautological. If so, check out:
<a href="http://www.talkorigins.org/faqs/evolphil/tautology.html" target="_blank">www.talkorigins.org/faqs/evolphil/tautology.html</a>

bluefugue · 01-03-2002, 03:14 PM

The expression "survival of the fittest" can be considered tautological, because it boils down to "that which survives, survives."

However, asserting natural selection as a mechanism for evolution is not circular or tautological. It makes a clear statement, to wit: the differential success of varying, replicating entities, will over successive generations cause those variations to accumulate as substantial morphological changes.

It's really a matter of semantics more than anything else, I think.

theyeti · 01-03-2002, 03:36 PM

A tautology, IIRC, is something that must be true by logical necessity. So claiming that natural selection is tautological will not help argue against its being true.

I actually do think that it must be true by logical necessity given certain conditions. Those conditions, however, are not required to be true and can be falsified by observing nature. Those conditions are overpopulation, heredity, and differential sucess in survival and reproduction. Given those conditions, you will have change due to natural selection.

theyeti

BLoggins02 · 01-03-2002, 04:24 PM

From yourDictionary.com -

Quote:

tautology - 1 a : needless repetition of an idea, statement, or word b : an instance of tautology
2 : a tautologous statement

OK, that was a big help, let's try "tautologous"

Quote:

1 : involving or containing rhetorical tautology : REDUNDANT
2 : true by virtue of its logical form alone
- tau.tol.o.gous.ly adverb

Hmm, what a "tautological" way to degine "tautology"

oh well...

Can anyone do any better, I've suddenly become lazy

BLoggins02 · 01-03-2002, 04:27 PM

..but, IMHO "that which survives, survives" is not "circular". It is the same as saying "that which is red, is red". Maybe it doesn't tell us much about what "red" is, but it doesn't defeat itself either.

Of course, if you look up "natural selection" in a biology textbook I doubt you will find the definition "that which survives, survives"

bluefugue · 01-03-2002, 05:15 PM

You're right, "circular" is the wrong way to characterize "that which survives, survives." It is tautological, though.

Cichli Suite · 01-03-2002, 05:17 PM

Quote:

The atheist admits that he thought natural selection sounded circular.

The atheist admits that he thinks natural selection is "circular" on what basis...?
Does this "hypothetical atheist" know anything about "circular arguements"?
Does this "hypothetical atheist" know enough about evolution, so that he can decide whether evolution is "circlar"?

My answer would be no to either question.

Quote:

Did I miss something?

No, i dont think you did.

MrDarwin · 01-03-2002, 06:18 PM

Natural selection is an observation of the real world. Organisms produce more offspring than can possibly survive. That is an observation. Some of these offspring survive to reproduce; some do not. That is another observation. Some genes make these offspring better able to survive and reproduce; some genes make them less able to survive and reproduce. These are all pretty basic and uncontroversial observations; as such, there is nothing "circular" about them.

In fact, most creationists claim not to have a problem with the concept of natural selection; they have a problem with natural selection resulting in "macroevolution" (although they usually define "macroevolution" quite differently than do evolutionary biologists, but that's another issue).

Detached9 · 01-04-2002, 01:14 AM

Precisely my point... this hypothetical atheist (strawman atheist as I call it) lead to an easy debate for the christian, an easy win. The atheist became a christian at the end of the book --- sad.

01-03-2002, 03:05 PM	#1
Detached9 Regular Member Join Date: Mar 2001 Posts: 341	Natural Selection is Circular? I was reading a book that is basically a dialogue between a christian and an atheist. The atheist admits that he thought natural selection sounded circular. The christian of course agrees and then they move on and consider the argument for natural selection being circular to not be required. Did I miss something?

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01-03-2002, 03:11 PM	#2
Darwin's Finch Senior Member Join Date: Sep 2001 Location: Gardnerville, NV Posts: 666	I assume you are referring to the old saw that natural selection is tautological. If so, check out: <a href="http://www.talkorigins.org/faqs/evolphil/tautology.html" target="_blank">www.talkorigins.org/faqs/evolphil/tautology.html</a>

01-03-2002, 03:14 PM	#3
bluefugue Veteran Member Join Date: Aug 2001 Location: Los Angeles Posts: 1,427	The expression "survival of the fittest" can be considered tautological, because it boils down to "that which survives, survives." However, asserting natural selection as a mechanism for evolution is not circular or tautological. It makes a clear statement, to wit: the differential success of varying, replicating entities, will over successive generations cause those variations to accumulate as substantial morphological changes. It's really a matter of semantics more than anything else, I think.

01-03-2002, 03:36 PM	#4
theyeti Veteran Member Join Date: Jun 2001 Location: Denver, CO, USA Posts: 9,747	A tautology, IIRC, is something that must be true by logical necessity. So claiming that natural selection is tautological will not help argue against its being true. I actually do think that it must be true by logical necessity given certain conditions. Those conditions, however, are not required to be true and can be falsified by observing nature. Those conditions are overpopulation, heredity, and differential sucess in survival and reproduction. Given those conditions, you will have change due to natural selection. theyeti

01-03-2002, 04:27 PM	#6
BLoggins02 Regular Member Join Date: Dec 2001 Location: College Station, TX Posts: 254	..but, IMHO "that which survives, survives" is not "circular". It is the same as saying "that which is red, is red". Maybe it doesn't tell us much about what "red" is, but it doesn't defeat itself either. Of course, if you look up "natural selection" in a biology textbook I doubt you will find the definition "that which survives, survives"

01-03-2002, 05:15 PM	#7
bluefugue Veteran Member Join Date: Aug 2001 Location: Los Angeles Posts: 1,427	You're right, "circular" is the wrong way to characterize "that which survives, survives." It is tautological, though.

01-03-2002, 06:18 PM	#9
MrDarwin Veteran Member Join Date: May 2001 Location: Washington, DC Posts: 4,140	Natural selection is an observation of the real world. Organisms produce more offspring than can possibly survive. That is an observation. Some of these offspring survive to reproduce; some do not. That is another observation. Some genes make these offspring better able to survive and reproduce; some genes make them less able to survive and reproduce. These are all pretty basic and uncontroversial observations; as such, there is nothing "circular" about them. In fact, most creationists claim not to have a problem with the concept of natural selection; they have a problem with natural selection resulting in "macroevolution" (although they usually define "macroevolution" quite differently than do evolutionary biologists, but that's another issue).

01-04-2002, 01:14 AM	#10
Detached9 Regular Member Join Date: Mar 2001 Posts: 341	Precisely my point... this hypothetical atheist (strawman atheist as I call it) lead to an easy debate for the christian, an easy win. The atheist became a christian at the end of the book --- sad.

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