Re: Revised Tautology FAQ

On Aug 1, 9:35 pm, j...@xxxxxxxxxxxxx (John S. Wilkins) wrote:
For a long time I have been unhappy about the Tautology FAQ here:

http://www.talkorigins.org/faqs/evolphil/tautology.html

Now Ivar Ylvisaker and I have produced a revised and simpler, less
pretentious, version, mostly Ivar.

Suggested New FAQ Tautology Page:

Summary: The claim that evolutionary theory is a tautology rests on a
misunderstanding of the theory. Fitness is more than just survival.

The simple version of the so-called 'tautology argument' is this:

Natural selection is the survival of the fittest. The fittest are those
that survive. Therefore, evolution by natural selection is a tautology
(a circular definition).

There is a flaw in this argument.  Arguably, "survival of the fittest"
has become an alternative name for the theory of natural selection.
However, the name of a thing usually does not fully describe the thing
that is named and that is true here.  The theory of natural selection is
more than just the idea of a "survival of the fittest."  In particular,
the theory of natural selection incorporates the idea of inheritance.  A
rudimentary example of a natural selection process is this:

 1.  Some animals in a species have an advantageous trait; for example,
they can run faster.

 2.  Hence, they are more likely to outrun predators.

 3.  Hence, they are likely to live longer.

 4.  Hence, they are more likely to have offspring.

 5.  Their offspring inherit the advantageous trait.

 6.  The process repeats; go back to 1.

The result is that the number of animals with this advantageous trait is
likely to increase.  The reverse is true of animals without the trait
(i.e., they are less likely to survive until they can reproduce).  The
second sentence in the 'tautology argument' above ignores heredity.  It
describes a more general concept.  But this means that the theory of
natural selection and the idea of the "survival of the fittest" are not
logical equivalents and, hence, there is no tautology.

It is worth noting that, even though the 'tautology argument' is
supposed to demonstrate that evolution is untestable, there is
widespread agreement that, at least, microevolution is testable.
Phillip Johnson, no friend of Darwinism, writes that "...everyone agrees
that microevolution occurs, including creationists" (Darwin on Trial,
page 68).  People who try to breed faster horses or to breed smaller
dogs (e.g., to create cute, tiny pets for city dwellers) or to breed
more productive strains of wheat are all, in effect, testing the theory
of natural selection.  Examples of natural selection in nature include
the peppered moth and the finches of the Galapagos Islands.  (For
evidence that macroevolution is testable, see 29 Evidences for
Macroevolution.)

Karl Popper [1976: sect. 37] also had doubts about whether "Darwinism"
was a testable scientific theory.  According to Popper, any situation
where species exist is compatible with Darwinian explanation, because if
those species were not adapted, they would not exist. That is, Popper
says, we define adaptation as that which is sufficient for existence in
a given environment. Therefore, since nothing is ruled out, the theory
has no explanatory power, for everything is ruled in.

This is not true, as a number of critics of Popper have observed since
(e.g., Stamos [1996] [note 1]). Darwinian theory rules out quite a lot.
It rules out the existence of inefficient organisms when more efficient
organisms are about. It rules out change that is theoretically
impossible (according to the laws of genetics, ontogeny, and molecular
biology) to achieve in gradual and adaptive steps (see Dawkins [1996]).
It rules out new species being established without ancestral species.

All of these hypotheses are more or less testable, and conform to the
standards of science. The answer to this version of the argument is the
same as to the simplistic version - adaptation is not just defined in
terms of what survives. There needs to be a causal story available to
make sense of adaptation (which is why mimicry in butterflies was such a
focal debate in the teens and twenties). Adaptation is a functional
notion, not a logical or semantic a priori definition, despite what
Popper thought.

One thing that should be noted, is that in logic a tautology is
something that is _true by definition_. If natural selection
_were_ a tautology, that would mean it had to be true, which is
perhaps a conclusion creationists would not want to reach.


http://scienceblogs.com/evolvingthoughts/2008/03/can_a_christian_accept_natural.php

"I once sat across the table from Alex Rosenberg, a well known
philosopher, who argued persuasively that one cannot be both a
Christian and accept natural selection. I think Alex intended this as
a reductio for Christianity, as natural selection is both true by
definition and also observed in the real world" (John Wilkins).

<end>

Any and all comments, criticisms and so forth are welcomed. I may add a
more philosophical "side-FAQ" to this later, if life permits.
--
John S. Wilkins, Philosophy, University of Sydneyhttp://evolvingthoughts.net
But al be that he was a philosophre,
Yet hadde he but litel gold in cofre

I am awaiting explanation for the apparent contradiction.

Ray

.

Loading