Asking the Right Questions, A Guide to Critical Thinking, 8th Ed

How Good Is the Evidence 11? 131
possibly be in favor of a tax that is the equivalent of the Holocaust? However,
we must evaluate the analogy to see whether it is really accurate or simply
an emotion-laden comparison intended to coerce people into agreeing with
a certain perspective by making the alternative seem ridiculous. After all,
regardless of what one thinks about the estate tax, it is not responsible for the
deaths of millions of people. Overly emotional analogies cloud the real issues
in arguments and prevent substantive discourse. Try to identify comparisons
made that contain significant emotional connotations to avoid being deceived
by these analogies.
Evaluating Analogies
Because analogical reasoning is so common and has the potential to be both
persuasive and faulty, you will find it very useful to recognize such reasoning and
know how to systematically evaluate it. To evaluate the quality of an analogy, you
need to focus on two factors.
1. The number of ways the two things being compared are similar and
different.
2. The relevance of the similarities and the differences.
A word of caution: You can almost always find some similarities between
any two things. So, analogical reasoning will not be persuasive simply because
of many similarities. Strong analogies will be ones in which the two things we
compare possess relevant similarities and lack relevant differences. All analogies
try to illustrate underlying principles. Relevant similarities and differences are ones
that directly relate to the underlying principle illustrated by the analogy.
Let's check out the soundness of the following argument by analogy.
I do not allow my dog to run around the neighborhood getting into trouble, so
why shouldn't I enforce an 8 o'clock curfew on my 16-year old? I am responsible
for keeping my daughter safe, as well as responsible for what she might do when
she is out. My dog stays in the yard, and I want my daughter to stay in the house.
This way, I know exactly what both are doing.
A major similarity between a pet and a child is that both are thought of as
not being full citizens with all the rights and responsibilities of adults. Plus,
as the speaker asserts, he is responsible for keeping his dog and daughter
safe. We note some relevant differences, however. A dog is a pet who lacks
higher order thinking skills and cannot assess right and wrong. A daughter,