Science,
we are told, is tentative. And given the history of science, there is every
reason for science to be tentative. No scientific theory withstands revision
for long, and many are eventually superseded by theories that flatly
contradict their predecessors. Scientific revolutions are common, painful,
and real. New theories regularly overturn old ones, and no scientific theory
is ever the final word.
But if science is tentative, scientists are not. As philosopher of science
Thomas Kuhn rightly noted, it takes a revolution to change scientific
theories precisely because scientists do not hold their theories tentatively.
Thus, in his Structure of Scientific Revolutions, Kuhn quotes with
approval Max Planck, who wrote: "A new scientific truth does not triumph
by convincing its opponents and making them see the light, but rather because
its opponents eventually die, and a new generation grows up that is familiar
with it."
No scientist with a career invested in a scientific theory is going to
relinquish it easily. And a good thing that is! The only way to make headway
with a theory is to be fully invested in it. Scientific theories are
frameworks for solving problems. Scientists risk their careers and
livelihoods working on theories they hope will solve interesting problems.
Consequently, scientists need to be persuaded that their theories provide not
only fundamental and profound insights, but also avenues of research
sufficiently fruitful to span an entire scientific career (typically forty or
so years).
By itself a scientist's lack of tentativeness poses no danger to science. It
only becomes a danger when it turns to dogmatism. Typically, a scientist's
lack of tentativeness toward a scientific theory simply means that the
scientist is convinced the theory is substantially correct. Scientists are
fully entitled to such convictions. On the other hand, scientists who hold
their theories dogmatically go on to assert that their theories cannot
be incorrect. How can a scientist keep from descending into dogmatism? The
only way I know is to look oneself squarely in the mirror and continually
affirm: I may be wrong . . . I may be massively wrong . . . I
may be hopelessly and irretrievably wrong--and mean it! It's not enough
just to mouth these words. We need to take them seriously and admit that they
can apply even to our most cherished scientific beliefs.
A simple induction from past scientific failures should be enough to convince
us that the only thing about which we cannot be wrong is the possibility that
we might be wrong. This radical skepticism cuts much deeper than Cartesian
skepticism, which always admitted some privileged domains of knowledge that
were immune to doubt (for Descartes mathematics and theology constituted such
domains). At the same time, this radical skepticism is consonant with an
abiding faith in human inquiry and its ability to render the world
intelligible. Indeed, the conviction with which scientists hold their
scientific theories, so long as it is free of dogmatism, is just another word
for faith. This faith sees the scientific enterprise as fundamentally
worthwhile even if any of its particular claims and theories are subject to
ruin.
In place of faith in the scientific enterprise, dogmatism substitutes
unreasoning certainty in particular claims and theories of science. Now the
problem with dogmatism is that it is always a form of self-deception. If
Socrates taught us anything, it's that we always know a lot less than we
think we know. Dogmatism deceives us into thinking we have attained ultimate
mastery and that divergence of opinion is futile. Self-deception is the
original sin. Richard Feynman put it this way: "The first principle is
that you must not fool yourself, and you are the easiest person to
fool." What's more, Feynman was particularly concerned about applying
this principle to the public understanding of science: "You should not
fool the laymen when you're talking as a scientist.... I'm talking about a
specific, extra type of integrity that is [more than] not lying, but bending
over backwards to show how you're maybe wrong."
I open with these general remarks about tentativeness and dogmatism in
science because their importance is too frequently neglected in discussions
of biological evolution. It hardly makes for a free and open exchange of
ideas when biologist Richard Dawkins asserts, "It is absolutely safe to say
that if you meet somebody who claims not to believe in evolution, that person
is ignorant, stupid, or insane (or wicked, but I'd rather not consider
that)." Nor does philosopher Michael Ruse help matters when he trumpets,
"Evolution is a fact, fact, FACT!" Nor for that
matter does Stephen Jay Gould's protegè Michael Shermer promote insight into
natural selection when he announces, "No one, and I mean no one,
working in the field is debating whether natural selection is the driving
force behind evolution, much less whether evolution happened or not."
Such remarks, and especially the attitude behind them, do nothing to settle
the ongoing controversy over evolution. Gallup polls consistently indicate
that only about ten percent of the U.S. population accepts the sort of
evolution advocated by Dawkins, Ruse, and Shermer, that is, evolution in
which the driving force is the Darwinian selection mechanism. The rest of the
population is committed to some form of intelligent design. Now it goes
without saying that science is not decided in an opinion poll. Nevertheless,
the overwhelming rejection of Darwinian evolution in the population at large
is worth pondering. Although Michael Shermer exaggerates when he claims that
no research biologist doubts the power of natural selection, he is certainly
right in claiming that this is the majority position among biologists.
Why has the biological community failed to convince the public that natural
selection is the driving force behind evolution and that evolution so conceived
(i.e., Darwinian evolution) can successfully account for the full diversity
of life? This question is worth pondering since in most other areas of
science the public readily signs off on the considered judgments of the
scientific community. Why not here? Steeped as our culture is in the
fundamentalist-modernist controversy, the usual answer is that religious
fundamentalists, blinded by their dogmatic prejudices, willfully refuse to
acknowledge the overwhelming case for Darwinian evolution.
Although there may be something to this charge, fundamentalist intransigence
cannot be solely responsible for the overwhelming rejection of Darwinian
evolution by the public. Fundamentalism in the sense of strict biblical
literalism is a minority position among religious believers. Most religious
traditions do not make a virtue out of alienating the culture. Despite
postmodernity's inroads, science retains tremendous cultural prestige. The
religious world by and large would rather live in harmony with the scientific
world. Most religious believers accept that species have undergone
significant changes over the course of natural history and therefore that
evolution in some sense has occurred (consider, for instance, Pope John Paul
II's recent endorsement of evolution). The question for religious believers
and the public more generally is not the fact of evolution but the mechanism
of evolutionary change--that chance and necessity alone are enough to explain
life.
I submit that the real reason the public continues to resist Darwinian
evolution is because the Darwinian mechanism of chance variation and natural
selection seems inadequate to account for the full diversity of life. One
frequently gets the sense from reading publications by the National Academy
of Science, the National Center for Science Education, and the National
Association of Biology Teachers that the failure of the public to accept
Darwinian evolution is a failure in education. If only people could be made
to understand Darwin's theory properly, so we are told, they would readily
sign off on it.
This presumption--that the failure of Darwinism to be accepted is a failure
of education--leads easily to the charge of fundamentalism once education has
been tried and found wanting. For what else could be preventing Darwinism's
immediate and cheerful acceptance except religious prejudice? It seems
ridiculous to convinced Darwinists that the fault might lie with their theory
and that the public might be picking up on faults inherent in their theory.
And yet that is exactly what is happening.
The public need feel no shame at disbelieving and openly criticizing
Darwinism. Most scientific theories these days are initially published in
specialized journals or monographs, and are directed toward experts assumed
to possess considerable technical background. Not so Darwin's theory. The
locus classicus for Darwin's theory remains his Origin of Species. In
it Darwin took his case to the public. Contemporary Darwinists likewise
continue to take their case to the public. The books of Richard Dawkins,
Daniel Dennett, Stephen Jay Gould, E. O. Wilson, and a host of other
biologists and philosophers aim to convince a skeptical public about the
merits of Darwin's theory. These same authors commend the public when it
finds their arguments convincing. But when the public remains unconvinced,
commendation turns to condemnation. Daniel Dennett even recommends
"quarantining" parents who teach their children to doubt Darwinism
(see the end of his Darwin's Dangerous Idea).
How is it that the public is commended for its scientific acumen when it
accepts Darwinian evolutionary theory, but disparaged for its scientific
insensibility when it doubts that same theory? The mark of dogmatism is to
reward conformity and punish dissent. If contemporary science does indeed
belong to the culture of rational discourse, then it must repudiate dogmatism
and authoritarianism in all guises. If the public can be trusted to evaluate
the case for Darwinism--and this is what Darwinists tacitly assume whenever
they publish books on Darwinism for the public--then it is unfair to turn
against the public when it decides that the case for Darwinism is
unconvincing.
Why does the public find the case for Darwinism unconvincing? Fundamentalism
aside, the claim that the Darwinian mechanism of chance variation and natural
selection can generate the full range of biological diversity strikes people
as an unwarranted extrapolation from the limited changes that mechanism is
known to effect in practice. The hard empirical evidence for the power of the
Darwinian mechanism is in fact quite limited (e.g., finch beak variation,
changes in moth coloration, and development in bacteria of antibiotic
resistance). For instance, finch beak size does vary according to
environmental pressure. The Darwinian mechanism does operate here and
accounts for the changes we observe. But that same Darwinian mechanism is
also supposed to account for how finches arose in the first place. This is an
extrapolation. Strict Darwinists see it as perfectly plausible. The public
remains unconvinced.
But shouldn't the public simply defer to the scientists--after all, they are
the experts? But which scientists? It's certainly the case that the majority
of the scientific community accepts Darwinism. But science is not decided at
the ballot box, and Darwinism's acceptance among scientists is hardly
universal. A growing movement of scientists known as "design
theorists" are advocating a theory known as "intelligent
design." Intelligent design argues that complex, information rich
biological structures cannot arise by undirected natural forces but instead
require a guiding intelligence. These are reputable scientists who argue
their case on strictly scientific grounds and who are publishing their
results in accepted academic outlets (cf. my own work, that of Jonathan
Wells, Siegfried Scherer, and others; cf. also www.baylor.edu/~polanyi).
Whether intelligent design is the theory that ultimately overturns Darwinism
is not the issue. The issue is whether the scientific community is willing to
eschew dogmatism and admit as a live possibility that even its most cherished
views might be wrong. Scientists have been wrong in the past and will
continue to be wrong, both in the niggling details and in the broad conceptual
matters. Darwinism is one scientific theory that attempts to account for the
history of life; but it is not the only scientific theory that could possibly
account for it. It is a widely disputed theory, one that is facing ever more
trenchant criticisms, and like any other scientific theory needs periodic
reality checks.
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