A lecture on one version of the classical design argument

1. Paley’s Analogy
D. Yeakel

2. The oldest
human
engraving
“Perhaps even more
intriguing is a single
shell with what
appears to be a
geometric pattern—
zigzagged grooves
carved into the center
of the outer shell.
Analysis points to the
patterns being carved
on purpose.”
From
Smithsonionmag.com

3. Evidence of
humans in
North America
at least 15,000
years ago
“A collection of
thousands of stone
artifacts supports the
theory that established
human groups were
spreading across North
America long before
Clovis technology
emerged.” From
Scientific American

4. Low Threshold for Design?
Think for a minute about the characteristics that show that the artifacts
were modified intentionally. Why do researchers universally accept
that the items were changed on purpose (or designed)?
Some have orderly markings or parallel lines.
There are conceivable uses for the objects; they have functionality.
What are some other characteristics you would look for if trying to
determine whether something had been designed?
Generate a list, and use it to evaluate the next few slides.

5. Hexagons are the optimal shape for
fencing regions with the most area
using the least fencing material.

6. The Fibonacci Sequence is a numerical
pattern that recurs in nature.

7. Planthoppers
have gears to
synchronize
their legs for
leaping.

8. Fractals are mathematical patterns
that repeat themselves at increasing
levels of magnification.

9. Paley’s Watch Paley asks you to
consider finding a
watch in the forest.
The features of the
watch that would
convince you that the
watch had a
designer—(apparent)
design, order,
contrivance, relation
of instruments to a
purpose,
subservience of
means to an end, and
sensitivity of
components—are
features also had by
the universe. Since
you’d conclude that
the watch has a
designer. You should
conclude that the
universe does too.

10. Paley’s Analogy
General Form of an
Analogy:
1) X and Y share
features: Q, R, S.
2) X has additional
feature P.
3) So, Y has feature P.
Paley’s Analogy
1) A watch and the universe share:
(apparent) design, order, contrivance,
subservience of means to an end,
relation of instruments to a purpose, and
sensitivity of components.
2) A watch has a designer.
3) So, the universe has a designer.

11. Evaluating Analogies
• As with any argument, it is an option to criticize the premises.
• Analogies are not valid—their premises do not guarantee their
conclusions. However, analogies can be strong—their premises can
make their conclusions likely.
• Analogies are stronger when there are more similarities and relevant
similarities between the objects. Similarities are relevant when they
relate to the category in the conclusion.
• In Paley’s argument the objects are a watch and the universe and the
listed similarities are (apparent) design, order…

12. The truth of the premises and the form
Premise one seems correct:
‘Relation of instruments to a purpose’
and ‘subservience of means to an end’
are similar. Both mean that parts are
used to accomplish a goal. There are
countless examples of this in the
universe. For just one example, see the
gears of the leafhopper.
‘Sensitivity of components’ means that
if small parts are removed or
rearranged, functionality is lost. This
happens in the universe at a small scale
(missing teeth on the gears would
disable the leafhopper) and a large scale
(if the strong nuclear force were slightly
different then stars and planets would
never have formed).
Premise two is indisputable.
The similarities listed in premise one are
obviously relevant to having a designer.
Are the similarities listed numerous
enough? What other characteristics are
there? How did you answer the earlier
question on slide four “what would you
look for?”
There aren’t any obvious omissions
from Paley’s list, right? So the form
looks good.

13. Criticisms of the form and replies
Dissimilarities
1. The universe has parts we don’t
understand but the watch does
not.
2. The universe has parts that seem
not to work perfectly.
3. Parts of the universe can
reproduce themselves.
4. The universe is much larger than
the watch.
5. Radical Dissimilarity: Aren’t the
two things just so different in so
many ways that comparison is
silly?
Replies (modify the watch)
1. Suppose the watch had parts we
didn’t understand. Wouldn’t you
still think it had a designer?
2. Suppose you found a watch with
parts that seemed broken.
Wouldn’t you still think it had a
designer?
3. Suppose you found a watch that
could reproduce. Wouldn’t you
think it had an amazing designer?
4. You’d still think a much larger
watch had a designer.

14. A premise one criticism:
Is premise one of Paley’s analogy correct? Does the universe have
parts that work together for a purpose? What is the purpose of the
universe? Maybe it has a purpose, but it doesn’t OBVIOUSLY have one.
A critic says the universe has no purpose.
What is the ‘end’ to which the means are put? Some parts of the
universe have an end, goal, or purpose, but that doesn’t mean that the
entire universe does. (Remember the fallacy of composition?)
Maybe Paley could fix the argument to avoid the premise criticism and
the radical dissimilarity criticism (of the form). He needs something
that’s of roughly the same size and complexity as a watch and that
obviously has a purpose.

16. Paley’s Revised Analogy
1) A watch and an eye share: (apparent) design, order, contrivance,
subservience of means to an end, relation of instruments to a purpose,
and sensitivity of components.
2) A watch has a designer.
3) So, an eye has a designer.
This conclusion no longer implies that the universe has a designer. Just
because a part of the universe does, doesn’t mean the whole thing does.
(Remember the fallacy of composition?) However, the conclusion is still
significant. Who but God is likely to be the designer of the eye? Not any
human being. A powerful alien? Absurd. Evolution? Impossible. Natural
selection is not a design process. It is a series of random mutations.

17. Criticisms?
David Hume pointed out that the conclusion might not work as an
argument for the existence of a perfect God. Supposing the analogy
works, he says, we should follow it all the way: imperfections in a watch
reveal an imperfect designer. Likewise, malfunctioning eyes should, by
Paley’s revised analogy, reveal an imperfect designer.
Paley could respond by saying that his analogy can’t be used for that
conclusion since the similarities of his argument (design, order, etc.)
aren’t relevant to imperfections, but to having a designer. Whether or
not that reply works, Hume’s objection is not a criticism of Paley’s
revised analogy, but rather to using it’s conclusion as an argument for a
perfect God.
See if YOU can criticize the revised analogy. There are only two types of
criticism possible: false premise and bad form. See if you can say how
an evolutionary biologist might respond.