There are people who, quite wrongly and
illogically, say you can neither prove
nor disprove the existence of god,
therefore there is an exactly fifty-percent
probability of god existing.
It's like tossing a penny.
That, of course is, completely illogical.
Just because you cannot disprove something,
and the teapot example shows that, it
doesn't means the odds of it being there
are fifty- percent and you can quickly see
that with the example of the teapot.
I regard the hypothesis of the existence
of god as a scientific hypothesis.
And in this, I disagree with many of my
scientific colleagues, who feel that science and
religion have absolutely nothing to do with
each other, and you could be a perfectly
good scientist while your religious belief
is a purely private matter that has nothing
whatever to do with your science.
I think that's wrong, because a universe with a god
would be a completely different kind of
universe from one without, and the difference
would be a scientific difference.
God, by the way, could clinch the matter
in a heartbeat in his favor if he chose to
intervene, for example, at this very moment.
Audience: (laughter)
The only one of the traditional arguments
for god that is still widely used today
is the teleological argument-
sometimes called the Argument from Design.
It's the famous Watchmaker Argument,
surely one of the most superficially plausible
bad arguments ever discovered. Audience: (laughter)
And it's rediscovered by just about everybody,
until they learn the logical fallacy of it, and
or they learn Darwin's brilliant alternative.
In the familiar world of human artifacts,
things like watches computers, complicated
things that look designed, are designed.
To naive observers, it seems to follow that
similarly complicated things in the natural world
that look designed, things like eyes
and hearts, are designed too.
This is not just a bad argument by analogy, it's
a bad argument by statistical reasoning as well.
It's fallacious, but it carries an illusion of plausibility.
If you randomly scramble the fragments
of an eye or a heart a million times,
you probably won't hit on one that can
see or pump. This demonstrates that such
devices could not have been out together
by chance, by random chance. And there are many
people who think the only alternative to random
chance is design, because of the lamentable scientific
education of most British and American students.
Audience: (applause)
There are many people who simply don't know
what Darwinian Natural Selection is, and
therefore, the only alternative to chance
that many people can imagine is design.
The English astronomer Sir Fred Hoyle dramatized
his own version of that misunderstanding.
He suggested that a hurricane
blowing through a junkyard
would be as likely to assemble by luck
a Boeing 747 as that Natural Selection
could put together life as we know it.
Even before Darwin came along and gave
us the answer, the impotence of the
Argument from Design was glaring.
How could it ever have been a good idea
to postulate as an explanation for the
existence of complex, improbable things,
a designer who would have to be even more
complex and improbable than that
which he's being invoked to explain.
The entire argument is an obvious logical
non-starter, as the great philosopher David Hume
realized before Darwin was born. But what
Hume didn't know was the supremely elegant
alternative to both chance and design
that Darwin was to give to us.
Natural Selection is so stunningly powerful
and elegant, it not only explains the
whole of life, it raises our consciousness, and
boosts our confidence in science's future ability
to explain, probably everything else.
Essentially, what's wrong with creationism,
stroke Intelligent Design, there's no
difference by the way, is that it is
what the philosopher Daniel Dennett
calls a "skyhook."
A "skyhook" is a great hand that comes
out of the sky, unexplained, and starts
manipulating things in the world.
And superficially, it looks as though
this great hand is explaining something.
But of course, it explains nothing,
because it lacks an explanation itself.
That's a skyhook. The opposite of a
skyhook is a crane. A crane really does
do explanatory work. Natural Selection
is the crane par excellence.
Natural Selection is cumulative.
It starts from simple beginnings and
works up, by gradual degrees,
incremental degrees, to the
prodigious heights of complexity and
improbability that we see
in the living world.
Here's a couple examples of products of
Natural Selection, of the great crane of
cumulative Natural Selection.
On the right is a rose thorn, an
adaptation by roses to avoid being eaten.
And that thorn has been carved and shaped
by Natural Selection over many generations.
On the left, those are not rose thorns,
those are bugs. They too have been carved
and shaped by Natural Selection into the
shape of a rose thorn as protection
against their own predators.
Natural Selection is not just an alternative
to chance, it's the only ultimate alternative
to chance that's ever been suggested.
Design is a workable alternative,
but only in the short term.
Because you still have to explain
where the designer came from.
Francis Crick and Leslie Orgel,
distinguished molecular biologists, once
playfully speculated that life on this
planet may indeed have been designed.
This is their theory of directed panspermia,
whereby an alien intelligence from outer
space seeded our planet with a rocket
in whose nosecone were bacteria, and
that's where all of life sprang from.
They didn't really believe that,
but they put it forward as an
interesting hypothesis.
It's interesting from my point of view
because I see nothing wrong with it,
it could be right, it seems to be unlikely
but it could be right, but whatever
else you could say, it cannot be
the ultimate explanation, because
you still have to explain where
the alien intelligences from outer space
came from. Sooner or later, that regress
has got to be terminated.
If those aliens from outer space were
themselves, seeded by another rocket
from a different planet,
you still haven't solved the problem.
Finally, you've got to terminate the regress
by postulating a crane instead of
a skyhook, and the obvious crane would
be evolution by Natural Selection.
The logic of Creationist arguments
is always the same; some natural
phenomenon is too statistically improbable
too complex, too beautiful, too awe-inspiring
to have come into existence by chance.
Design is the only alternative to chance
that the author can imagine, therefore
design must have done it.
And science's answer to this faulty
logic is also always the same;
design is not the only alternative to chance,
Natural Selection is a better alternative.
Notice what rotten logic it is.
We have theory A and theory B.
Theory A is supported by loads of evidence,
Theory B is supported by no evidence at all.
Now here's the key step in the argument: four. Audience: (laughter)
I can't understand how theory A
explains phenomenon X, therefore
theory B must be right.
Audience: (laughter)
I bet you don't know how the elbow joint
of the lesser spotted weasel frog evolved.
Audience: (laughter)
You don't? Right then, god did it!
Audience: (laughter and applause)
This kind of argument is a
failure of the imagination.
I've described it as the
Argument from Personal Incredulity.
A metaphor for extreme improbability is
a combination lock. A very good,
high quality combination lock of the kind
that they put on bank vaults. A bank
robber could theoretically get lucky and
hit upon the right combination, and therefore
get all the money in the bank, but in practice,
combination locks, at least the ones in bank vaults,
are designed with enough improbability
to make this tantamount to impossible,
as unlikely as Fred Hoyle's spontaneous
coming into existence of a Boeing 747.