Evaluate the following arguments from analogy as either strong or weak. If the argument is weak, cite what you think would be a relevant disanalogy.

Question

1. Every painting by Rembrandt contains dark colors and illuminated
faces, therefore the original painting that hangs in my high school is
probably by Rembrandt, since it contains dark colors and illuminated
faces.
2. I was once bitten by a poodle. Therefore, this poodle will probably
bite me too.
3. Every poodle I’ve ever met has bitten me (and I’ve met over 300
poodles). Therefore this poodle will probably bite me too.
4. My friend took Dr. Van Cleave’s logic class last semester and got an A.
Since Dr. Van Cleave’s class is essentially the same this semester and
since my friend is no better a student than I am, I will probably get an
A as well.
5. Bill Cosby used his power and position to seduce and rape women.
Therefore, Bill Cosby probably also used his power to rob banks.
6. Every car I’ve ever owned had seats, wheels and brakes and was also
safe to drive. This used car that I am contemplating buying has seats,
wheels and brakes. Therefore, this used car is probably safe to drive.
7. Every Volvo I’ve ever owned was a safe car to drive. My new car is a
Volvo. Therefore, my new car is probably safe to drive.
8. Dr. Van Cleave did not give Jones an excused absence when Jones
missed class for his grandmother’s funeral. Mary will have to miss
class to attend her aunt’s funeral. Therefore, Dr. Van Cleave should
not give Mary an excused absence either.
9. Dr. Van Cleave did not give Jones an excused absence when Jones
missed class for his brother’s birthday party. Mary will have to miss
class to attend her aunt’s funeral. Therefore, Dr. Van Cleave should
not give Mary an excused absence either.
10. If health insurance companies pay for heart surgery and brain surgery,
which can both increase an individual’s happiness, then they should
also pay for cosmetic surgery, which can also increase an individual’s
happiness.
11. A knife is an eating utensil that can cut things. A spoon is also an
eating utensil. So a spoon can probably cut things as well.
12. Any artificial, complex object like a watch or a telescope has been
designed by some intelligent human designer. But naturally occurring
objects like eyes and brains are also very complex objects. Therefore,
complex naturally occurring objects must have been designed by
some intelligent non-human designer.
13. The world record holding runner, Kenenisa Bekele ran 100 miles per
week and twice a week did workouts comprised of ten mile repeats on
the track in the weeks leading up to his 10,000 meter world record. I
have run 100 miles per week and have been doing ten mile repeats
twice a week. Therefore, the next race I will run will probably be a
world record.
14.I feel pain when someone hits me in the face with a hockey puck. We
are both human beings, so you also probably feel pain when you are
hit in the face with a hockey puck.
15.The color I experience when I see something as “green” has a
particular quality (that is difficult to describe). You and I are both
human beings, so the color you experience when you see something
green probably has the exact same quality. (That is, what you and I
experience when we see something green is the exact same
experiential color.)

Answer 1

1. Weak: if the painting is hanging in your high school, it probably isn’t a
Rembrandt. That is the disanalogy: even if the colors are very similar,
almost all Rembrandts hang in galleries, not in high schools.
2. Weak. Although the similarity is that they are both poodles, there is
probably some other characteristic that accounted for me being bitten.
That is, it probably wasn’t the fact that the dog that bit me was a poodle,
but more likely that I was invading its space or it felt threatened, etc. It
could have likely been some other breed in the same circumstances. So
it isn’t “poodleness” that accounts for the biting. That said, if we had
evidence that poodles are much more likely to bite than other breeds
then this argument would be stronger.
3. Strong. Unlike, the last one, this argument delivers a much stronger
analogy between past events (poodle-encounters and poodle-bitings)
and the current event (poodle-encounter).
4. Strong. The relevant similarities are: 1) Van Cleave’s class doesn’t change
much from semester to semester, 2) the person has the same abilities as
their friend who got the A.
5. Weak. Although both are crimes, there are many relevant differences
between committing rape and robbing a bank.
6. Weak. There is no particular relationship between having seats, wheels,
and brakes, on the one hand, and being safe to drive, on the other. So
having seats, wheels and brakes is not a relevant similarity between the
two cars, if what we are interested in is how safe they are.
7. Strong. The car company (Volvo) is a relevant similarity between the old
cars and the new car. We can expect similar quality between cars from
the same company. In contrast, knowing that a car as wheels, brakes and
seats tells us essentially nothing about its quality, including its safety.
8. Strong.
9. Weak. A birthday party and a funeral are not relevantly similar in this case.
A funeral is a much more important family event than a birthday party
(typically). So we should not expect similarity with respect to a
professor’s absence policy when comparing birthday parties to funerals.
10. Weak. Although both may influence happiness, the relevant difference is
that whereas heart and brain surgery are typically a matter of life and
death (and hence much more likely to be paid for by insurance), cosmetic
surgery is not a matter of life and death.
11. Weak. Although a knife and spoon share the property of being eating
utensils, that is not a relevant similarity on which we can expect that they
will share functional properties like cutting.
12. Whether this famous argument for the existence of God is strong or weak
is a matter of some debate. One reason for saying it is a weak argument
is that there is a disanalogy between artificial objects and natural objects,
since complex natural objects may evolve without being designed by an
intelligent designer, whereas no artificial objects (yet) can evolve on their
own.
13. Weak. Running the same number of miles as an elite runner is not a
relevant similarity for determining how fast one will run a race. The
relevant dissimilarity here is that although Bekele runs his mile repeats at
close to 4:00 flat, I can only run mine at 5:30. So it is the pace at which
one runs, rather than the number of miles one runs, that is the better
predictor of how fast one can run a race.
14. Strong. The fact that we are both humans is relevant to determining
whether someone will feel pain. Humans all have similar physiology,
which is why we should expect that if x causes one person physical pain,
then x will also cause anyone else a similar pain. (However, this argument
also raises a famous problem in philosophy of mind called “the problem
of other minds.” The issue is whether or not we can ever know that
people have mental states, such as pain, like my own. Even if you exhibit
pain behavior in similar instances in which I experience pain, how do I
know that you are actually feeling what I am feeling—that you are having
the experience of pain, rather than simply exhibiting pain behavior
without have the mental experience of it? Many philosophers have
argued that we cannot overcome this problem and must admit that we
cannot know whether people other than ourselves actually have mental
states like ours.)
15. Again, the common sense answer would be that this is a strong
argument based on a strong analogy. Since you and I are both human
and share similar perceptual systems, we should expect that we will
perceive the world very similarly (even if not exactly the same). (However,
we can raise the same “problem of other minds” problem here as I did in
#14 above. Suppose we both point at the grass and say that it is green.
However, how do I know that your experience of green is like my
experience of green? Maybe your experience of green is more like my
experience of red and vice versa.)