266 Unit 7 Critical reasoning: Advanced Level
objection to the argument that merely points
out random differences has little value. The
relevance of the comparison must be
considered. With that in mind, it is really
quite difficult to fault C. If it is right to make
people wear seatbelts, on the grounds that it
saves both lives and public money, then it is a
very fair point that cyclists should take the
same precautions, and face the same
compulsions. You might say that bicycles are
slower than cars; but unless that translates
into fewer accidents or injuries, that is
irrelevant. You might be tempted to object that
cyclists have a right to take risks with their
own lives. But that would apply to drivers and
the wearing of seatbelts too. The analogy
remains fair – in the relevant respect.
Argument from analogy is especially
effective in counter-arguments and debates.
Here is an example of two people – we’ll call
them K and J – disputing the merits of reality
television, especially the programme called Big
Brother, in which a number of people are
confined to a house and filmed night and day.
We take up the debate at a point where J has
just said that the Big Brother housemates are
‘manipulated and exploited like circus animals’.
(There is one analogy already.) She goes on:J: That pathetic lot in the house think they
are celebrities, when really they are just
sad little victims making fools of
themselves for public entertainment.
And the only reality is they’re too stupid
to know it.
K: Don’t you think that’s a bit patronising?
J: It’s the truth.
K: How do you know? You never watch it;
you’ve admitted that. You can’t criticise
something you’ve never watched.
J: Yes I can. I’ve never watched a public
execution, but I know it’s wrong.
Therefore I wouldn’t watch.
K: That’s different, and you know it.
J: What’s different about it?
K: No one’s killed on Big Brother.Argument from analogy has the following
general form: If such-and-such a thing is true
of X, and Y is like X (in the relevant respect),
then the same thing is true of Y. So, if one
ought to be made to wear a seatbelt in a car,
one ought to be made to wear a helmet on a
bike, because – arguably – there is no relevant
difference.Activity
Do you accept this argument? Is the analogy
in C fair, or fit for purpose as a premise in the
argument?Commentary
This will be quite brief. The answer to the first
question is up to you: evaluating arguments of
this sort very often comes down to whether
you think the analogy is a good one or not. But
that does not mean that arguments from
analogy cannot be evaluated with some
objectivity. The heart of the matter is whether
or not the analogy is a fair one: whether the
two things being compared are sufficiently
alike for the conclusion to apply to both of
them. The key phrase in this is the one in
brackets and italics above: ‘in the relevant
respect’. Why must this be added?
The reason is this: an argument from
analogy does not depend on the compared
objects being exactly alike, or alike in every
respect, for they would then be identical.
Indeed, some of the best AfA compare objects
which are in many respects quite different.
(We’ll see an example of one shortly.) In C the
analogy is between cycling helmets and
seatbelts. It does not demolish the argument
to point out that one goes on your head and
the other across the lap and over the shoulder.
The relevant respect is the alleged reduction of
injury that both devices are meant to bring;
and in that respect, they are closely analogous.
When evaluating an AfA, therefore, it is
essential to bear this qualification in mind. An