Darwinism: Science or Philosophy - Chapter 11a

Response to Arthur M. Shapiro - X Does implicate Y: implication and Entailment in the Creation-Evolution Debate

by William A. Dembski
1994

This paper is a response to a presented paper.

Original author's comments on this response.


ARTHUR SHAPIRO HAS JUST argued that X does not entail Y, where X is
biological evolution of the Darwinian or neo-Darwinian stripe, and Y is
any particular position on the ultimate origins of life or the universe.
To this I offer a hearty Amen. But I also ask, So what? As a mathematician
I've had plenty of experience in the logic of entailment-every theorem is
entailed by some relevant set of mathematical axioms As a philosopher who
works in the logic of conditionals, I'm aware how entailment works outside
mathematical contexts. Entailment is the strongest logical connection by
far. To say that X entails Y is to say that it's impossible for X to be
true and Y false. Alternatively, Y is necessary given X. Thus, to say that
X does not entail Y is to say that it is possible for X to be true and Y
false. But since Shapiro leaves Y completely open-ended on the questions
of origins, to say that biological evolution does not entail any account
of origins, be it theistic, materialistic, or whatever, is simply to say
that biological evolution is logically compatible with any number of
positions on the origin of life and the universe.

Given what is meant by logical entailment-and this is the sense in which
Shapiro is using it-I must agree with his claim. Moreover, Shapiro's claim
has empirical support: individuals with widely divergent views on origins
have made their peace with, or (if you will) have surrendered to,
neo-Darwinism. Certainly this is true of "scientistic atheists" like Will
Provine. But it is also true of notable theists like Richard Swinburne,
who even when writing on teleology and design admits the central claims of
neo-Darwinism:

Complex animals and plants can be produced through generation by less
complex animals and plants . . . and simple animals and plants can be
produced by natural processes from inorganic matter.{1}

Suffice it to say, there is no logical impossibility reconciling
neo-Darwinism with a host of philosophical positions on origins.
So what? Suppose I place Al and Bob in a room, lock it, reopen it an hour
later only to find Al lying on the floor in a pool of blood, with Bob
standing over him holding a smoking gun. Denote this scenario by X. Let Y
denote the claim that Bob shot Al. Does X entail Y? Well, no. Al may have
been suicidal and shot himself. Bob tried to prevent this and is now
holding the gun which he was too late in taking away from Al. Suppose,
however, we know that Bob and Al are mortal enemies, and that Al has no
suicidal tendencies. With this background knowledge, does X entail Y?
Again the answer is No. There might be a trap door in the room. Perhaps an
enemy of both Al and Bob used the trap door to enter the room, shoot Al,
and then place the gun in Bob's hand so as to frame Bob.

If this story appears fanciful, if I appear to be veering from the path of
common sense, it is because the logic of entailment cannot distinguish
between the banal, the bizarre, and the ridiculous. It can distinguish
only between the possible and the impossible. The circumstantial evidence
for Bob's killing Al may be excellent if a video camera in the room
happens to record Bob shooting Al, there will even be direct evidence for
Bob shooting Al. But no amount of empirical evidence will entail Bob
shooting Al. Bob's double might actually have shot Al. Bob's enemy might
have rigged the video camera so that it only appears that Bob shot Al. I
am not suggesting that our reason for believing that Bob shot Al becomes
inferior because no evidence can entail this claim. Entailment is simply
too strong a logical notion to apply in most matters of fact. In
particular, it is the wrong philosophical tool for investigating the
relation between Darwinism and origins.

It is here that Shapiro and I part company. Shapiro argues, and I quote,
Biological evolution is no more inconsistent with religion than are
other sciences, and . . . the attacks on it specifically are best
understood in sociological and political, not philosophical, terms.
Philosophy has a lot more to say about the relation between biological
evolution and world views than Shapiro is willing to admit. To move from
entailment to sociology is simply too abrupt a leap. It is more than a
sociological fact that, and I quote Shapiro, "the phenomenal growth of
science in the last few centuries has been largely at the expense of
religion. By concentrating on entailment and jumping from there to
sociology, Shapiro has ignored the epistemological question of what
implications exist between Darwinism and religion.

In philosophy, implication is a more general notion than entailment. The
scenario of Al and Bob locked in a room together with some appropriate
background assumptions would implicate that Bob had murdered Al, but it
wouldn't entail that Bob had murdered Al. Implication includes entailment,
and therefore addresses questions of possibility and necessity. But
implication also addresses questions of uncertainty, partial evidence, and
probability. X can implicate Y without X having to force Y to be true
under all possible circumstances. X can implicate Y. X can be true, but Y
might still fail. Any lawyer will appreciate this point. As an aside, let
me mention that this is one reason why I appreciate Phillip Johnson's work
of weighing neo-Darwinism in the legal balances. A strict logico-deductive
argument will never settle the creation-evolution debate.

I've said that Shapiro ignores the epistemological question of what
implications exist between neo-Darwinism and theology. This is true in
that he admits no implication other than entailment. Nevertheless, without
assigning it any epistemological weight, he does mention a significant
implication. Commenting on natural selection Shapiro notes,

Darwin's great intellectual triumph was to provide a mechanism, natural
selection, that could account for . . . the appearance of design without
invoking a Designer. Clearly, the availability of such a mechanism would
gladden the heart of anyone who for whatever reason wished to banish God
from the universe. But it itself could not banish God from the universe.
If the mechanism works, if it is proven valid and sufficient, then it
renders God simply redundant in that context. But that is not to say
that it disproves His existence; it merely makes it a teensy bit less
necessary for explanatory purposes.

I would drop the "teensy bit less necessary" business, and simply admit
that if Darwin was right, then design is unnecessary for explaining the
complexity of living systems. This clearly is an implication. Note that it
is not an entailment. Note also that the concerns raised by this
implication are squarely epistemological, not sociological. The
implication states that a certain type of explanation becomes
insupportable if neo-Darwinism happens to be correct, namely, any
explanation that explains living systems as the product of design.
Now I agree wholeheartedly that this implication is correct. Swinburne
endorses it as well. I quoted Swinburne earlier as supporting the
fundamental thesis of neo-Darwinism, viz., that "complex animals and
plants can be produced through generation by less complex animals and
plants . . . and simple animals and plants can be produced by natural
processes from inorganic matter." Swinburne makes this claim at the same
time he is advancing an argument from design. How can he do this? By
looking to cosmology instead of biology. Indeed, he admits that Darwin has
banished design from biology.

Now Shapiro doesn't think that the implication "if neo-Darwinism is right,
then design is an unnecessary explanatory device" has much riding on it
theologically. For Shapiro it is enough that the existence of God remain
secure. As Shapiro has rightly observed, Darwinism entails nothing about
the existence of God. For theology, however, there is more at stake than
simply the existence of God. The nature of this God, his relation to the
world, and his causal powers to affect the world are part and parcel of
any theological position.

In terms of the logic of entailment it makes no big difference to the
existence of God whether Darwin was right or wrong. But in terms of the
logic of implication it can make a big difference to a theological
position whether Darwin was right. Shapiro's theology is certainly at
peace with Darwin. A strictly pietistic theology can without much
difficulty make peace with Darwin. A deistic theology can readily make
peace with Darwin. Only a theology so obtuse as to insist on biblical
inerrancy cannot make peace with Darwin; at least this is the impression
Shapiro leaves.

What are the implications of Darwinism for theology? Shapiro has correctly
argued that Darwinism does not entail any of the isms that contend with
religion. Shapiro has also argued, again correctly, that Darwinism
implicates the redundancy of design. Phillip Johnson (I believe rightly)
takes this implication a step further, viz., Darwinism implicates
naturalism. As Johnson puts it,

"Evolution" contradicts "creation" only when it is explicitly or tacitly
defined as fully naturalistic evolution-meaning evolution that is not
directed by any purposeful intelligence.

Once one realizes that natural selection is precisely the vehicle needed
to transform a theory of evolution into a fully naturalistic theory of
evolution, the implication follows at once. Darwinism does implicate
naturalism. The less God has to do, the less reason there is to maintain a
theology, the more reason there is to adopt naturalism. This is not a
sociological point. This is an epistemological point about the nature of
explanation-about not postulating entities that are redundant or
irrelevant. X therefore does implicate Y.

In closing this response, I feel it necessary to say a few words in
defense of Phillip Johnson. Shapiro has charged Johnson with "making the
same vulgar errors as appear routinely in the presentations of
professional creationists." There is only one error I can see Shapiro
referring to, and that is the error of claiming that Darwinism entails
naturalism (a claim that is false simply because God can always be
maintained as a useless appendage in any world view). That Johnson never
claimed such an entailment should have been obvious to Shapiro, since
Johnson as a lawyer is in the business of weighing evidence subject to
uncertainties, and not in the business of entailments involving necessary
connections. Shapiro's charge therefore cannot be supported.

Shapiro's criticism of Johnson, however, fails in a more serious way.
Shapiro claims that Darwinism does not entail naturalism. Johnson claims
that Darwinism implicates naturalism. Both are right. Nevertheless, I
would claim that Johnson's concern in writing Darwin on Trial was not
primarily with X entailing or implicating Y, where X is Darwinism and Y
naturalism, but Y implicating X. The reverse implication is really the
important one. Sure, Darwinism gives God less to do and therefore
implicates naturalism. But naturalism in turn needs something like
Darwinism to keep it viable.

As Alvin Plantinga puts it, if you accept naturalism, Darwinism is the
only game in town. Plantinga claims an implication from naturalism to
Darwinism. Johnson's work properly speaking is devoted to this
implication. As a lawyer concerned with how ideological agendas-and
naturalism is one such agenda-influence the courts, it is only natural for
Johnson to concentrate on this implication. Shapiro has therefore missed
the boat twice. The question was never whether X entails Y. It was always
obvious that X implicates Y. The central question was how Y implicates X,
i.e., how naturalism manages to keep Darwinasm afloat. Indeed, Darwinism
needs more than scientific facts to keep it afloat.

NOTE

{1} Richard Swinburne. The Existence of God (Oxford: Oxford University
Press, 1979), p. 135.

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