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chapter
Arguments and
Methodology
INTRODUCTION
We should accept philosophical views in general, and moral views in particular,
on the basis of the arguments offered in their support. It is therefore crucial
to understand what an argument is, and how to evaluate an argument. In this
chapter, we explain the kinds of arguments philosophers give, the features of
good and bad arguments, and some common tools and methods that will aid
in the evaluation of arguments.
Learning Objectives
After completing this chapter, you should be able to:
•
•
•
•
Distinguish deductive from inductive arguments
Define deductive validity and soundness
Explain inductive strength and weakness
Describe common fallacies when constructing and
evaluating arguments
• Recognize the role of moral principles when constructing
moral arguments
• Understand the nature and purpose of thought experiments
• Construct counterexamples to test philosophical analyses
and claims
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ARGUMENTS
What Is an Argument?
An argument is simply a set of at least two claims. One of these is the conclusion, and any other claims are premises. The conclusion is the claim that one
is trying to prove, and the premises are the reasons offered in support of the
conclusion. To illustrate, consider the following example:
(1) It is always wrong to kill an innocent person.
(2) Abortion is the killing of an innocent person.
(3) Therefore, abortion is wrong.
The conclusion of this argument is the claim that abortion is wrong. The
other two claims are the premises, or supporting reasons. Arguments must
have at least one premise, but there is no upper limit to the number of premises
an argument can have.
Sometimes the arguments given in support of a position are clearly and
explicitly stated. Other times, however, the arguments may be buried in difficult and lengthy passages. In these cases, it will take work to spot the conclusion and supporting premises. Often, certain terms are present that can
help you to piece together an author’s argument. Philosophers call these terms
premise indicators and conclusion indicators.
Premise indicators include the terms for, because, since, and given that.
Here are a few examples to illustrate how these terms are used in the context
of an argument.
Because active euthanasia involves the intentional killing of a
person, it is always wrong.
You should not deceive others, for this is disrespectful.
Since abortion is murder, it is wrong.
The following terms are conclusion indicators: therefore, thus, hence, so,
and consequently. Again, here are examples to show how some of these terms
are used to signal the conclusion of an argument.
Active euthanasia involves the intentional killing of a person.
Therefore, it is always wrong.
Deceiving others is disrespectful, so you should not deceive
others.
Abortion is murder; thus it is wrong.
In some instances, arguments may be given without the use of premise or
conclusion indicators. Determining the structure of an argument in such cases can
be tricky. You have to ask yourself what role each sentence is playing in the passage. If a particular sentence expresses the point the author is trying to prove, then
it is the author’s conclusion. If a sentence is given as support for some other claim,
then it is a premise. Still other sentences in the passage may not play a direct role
in the argument, and these would be neither the premises nor the conclusion.
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Upon finding a passage in a text that contains an argument, it is often
helpful to rewrite it in what is known as standard form. In standard form,
each premise is numbered and stated on its own line, and then the conclusion
is stated last. Usually, the conclusion is separated from the premises by a horizontal line, with the premises above the line and the conclusion below it. To
illustrate, consider the following argument:
Abortion is morally permissible, for it is morally permissible
for women to make their own decisions when it comes to
controlling their own bodies, and abortion is a decision that
involves women and their own bodies.
We can rewrite the argument in standard form as follows:
(1) It is morally permissible for women to make their own decisions when it
comes to controlling their own bodies.
(2) Abortion is a decision that involves a woman and her own body.
(3) Therefore, abortion is morally permissible.
There are numerous advantages in writing out an argument in standard form—
not the least of which is that it makes the argument clearer and thus easier to
evaluate.
Evaluating Arguments
The point of providing an argument in support of a view is typically to show
that the view is correct and to persuade others to accept it.1 Good arguments—
ones we should accept—have two features. First, all of the premises are true.
And second, the premises logically support the conclusion. Thus, when evaluating arguments, we need to ask two basic questions. First, are all of the premises true? Second, do the premises support the conclusion? If the answer to
both of these questions is “yes,” then the argument is a good one and we have
good reason to accept its conclusion. If, however, the answer to either question
(or both) is “no,” then the argument is bad and we do not have good reason
to accept its conclusion. Notice, then, that an argument might fail for one of
two reasons: it might have a false premise, or it might have premises that do
not support the conclusion. (Of course, an argument might have both of these
problems.)
It is important to recognize that whether the premises are true, and whether
the premises support the conclusion, are logically distinct issues. Consider the
following example:
(1) All patients have cancer.
(2) All cancer patients have appendicitis.
(3) Therefore, all patients have appendicitis.
1
Arguments can, of course, have different purposes. For example, in science, arguments can be
used to deduce predictions from general principles and observations.
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This, of course, is a bad argument. What makes it bad is not that the premises
fail to support the conclusion. In this example, the premises very strongly support the conclusion. If the premises were true, the conclusion would have to be
true.2 The problem with this argument is that the premises are not true. Now
consider an argument with the opposite problem:
(1) Some Canadians have cancer.
(2) Some Americans have arthritis.
(3) Therefore, a broken leg is painful.
This, too, is a bad argument. But what makes this argument bad is not that the
premises are false. Rather, the problem with this argument is that the premises
do not logically support the conclusion. Acceptance of the premises does not
give us any reason to accept the conclusion. Even though the premises are true,
the conclusion still could be false. It is important, then, not to assume that the
conclusion of an argument is true simply because the premises are true. The
premises must also logically support the conclusion.
Deductive Arguments: Validity and Soundness
A deductive argument is an argument where the truth of the premises is
intended to guarantee the truth of the conclusion. For example, the following
is likely offered as a deductive argument:
(1) It is seriously immoral to deprive an individual of a future of value.
(2) Abortion, in standard cases, deprives the fetus of a future of value.
(3) Therefore, in standard cases, abortion is seriously immoral.
When evaluating deductive arguments, there are certain technical terms that
philosophers commonly use. In particular, philosophers use the terms valid
and sound to refer to properties that deductive arguments can have or lack.
A deductively valid argument (or for simplicity’s sake, a valid argument) is an
argument with the following feature: It is impossible for all of the premises to
be true and the conclusion false. Put a little differently, if all of the premises
are true, the conclusion must be true. To illustrate, let’s return to an example
considered earlier:
(1) All patients have cancer.
(2) All cancer patients have appendicitis.
(3) Therefore, all patients have appendicitis.
Here’s another example:
(1) No Canadian is an American
(2) Wayne Gretzky is a Canadian.
(3) Therefore, Wayne Gretzky is not an American.
2
Arguments that have this feature are said to be valid. We discuss the concept of validity in the
following section.
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Notice that in each of these examples, if the premises were true, the conclusion
would have to be true. The truth of the premises logically guarantees the truth
of the conclusion. Hence, these are valid arguments.
It is very important to note that valid arguments need not have true premises. In saying that an argument is valid, we are not claiming that the premises
are true. We are claiming, rather, that the premises, if true, guarantee that the
conclusion is true. In other words, to say that an argument is valid is
to say something about the logical relationship between the
argument’s premises and its conclusion: the relationship is such
that if the premises are true, then the conclusion must be true.
DISCUSSION
Deductive arguments that do not have this property are said to
Can a valid argument have false
be invalid.
premises and a true conclusion?
A sound argument is a valid argument with all true premExplain your answer using an
ises. A virtue of sound arguments is that they always have true
example.
conclusions.3 Notice that this is guaranteed by the definition of a
sound argument. Here is a simple example of a sound argument:
UP FOR
(1) If mercy killing was illegal in Canada in 1993, then Robert Latimer broke
the law when he committed the mercy killing of his daughter, Tracy.
(2) Mercy killing was illegal in Canada in 1993.
(3) Therefore, Robert Latimer broke the law when he committed the mercy
killing of his daughter, Tracy.
This is a valid argument: if the premises are true, the conclusion must be true.
The premises, moreover, are in fact true. Hence, this argument is sound.
An unsound argument is a deductive argument that is either invalid or has
at least one false premise. Unsound arguments are therefore bad arguments.
They are bad because if an argument is unsound, it has failed to establish the
truth of its conclusion. Note, however, that this is not to say that the conclusions of unsound arguments must be false. To illustrate, here is an example of
an unsound argument with a true conclusion:
(1) Everyone who goes to a private clinic is terminally ill.
(2) Some Canadians go to private clinics.
(3) Therefore, some Canadians are terminally ill.
Here we have an unsound argument with a true conclusion. The argument is
unsound because premise (1) is false. Thus, when we claim that an argument
is unsound, we are not saying that its conclusion is false. Rather, we are saying
that its conclusion should not be accepted on the basis of this argument. Either
the argument is invalid, so the premises do not logically support the conclusion, or at least one premise is false, so the argument does not necessarily lead
us to the truth.
3
Notice, however, that not all sound arguments are informative or useful. Circular arguments,
for instance, may be sound, but not informative or useful. Here’s an example of a sound circular
argument: Cancer is sometimes fatal. Therefore, cancer is sometimes fatal.
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Inductive Arguments
Not all arguments are intended to be deductive arguments. In some arguments,
the premises, if true, may not be intended to guarantee the truth of the conclusion. Instead, the premises provided may be intended to demonstrate only that
the conclusion is probably true. In that case, the argument is inductive. Here is
an example of this kind of argument:
(1) Most healthy pregnancies at 24 weeks result in successful births.
(2) Tina has a healthy pregnancy at 24 weeks.
(3) Therefore, Tina’s pregnancy will result in a successful birth.
Now, the fact that healthy pregnancies at 24 weeks generally result in successful births does not guarantee or conclusively prove that Tina’s pregnancy will
result in a successful birth. That is, it is possible that the conclusion is false,
even if the premises are true. However, if the premises of the argument are true,
they certainly do provide some support for the conclusion. This support is not,
however, the kind of support we talked about earlier when we looked at valid
arguments. The premises just make the conclusion more probable.
When it comes to evaluating inductive arguments, philosophers do not
use the terms valid/invalid and sound/unsound; instead, they speak of inductive arguments as being either strong or weak. A strong inductive argument
is an argument which is not deductive, and where the premises, if true, make
the conclusion probably true. The more support provided by the premises of
an inductive argument, the stronger the argument. Here is an example of an
inductively strong argument:
(1) Dr. Badesh will see 100 flu sufferers this year.
(2) Dr. Badesh has treated 99 flu sufferers this year with antibiotics.
(3) Therefore, Dr. Badesh will treat all of the flu sufferers he sees this year
with antibiotics.
This is a strong inductive argument, because if the premises are true, it is likely
that the conclusion is true.4
An inductive argument is weak when the premises, if true, provide little support for the conclusion. Here is an example of an inductively weak
argument:
(1) Dr. Badesh will see 100 flu sufferers this year.
(2) Dr. Badesh has treated 1 flu sufferer this year with antibiotics.
(3) Therefore, Dr. Badesh will treat all of the flu sufferers he sees this year
with antibiotics.
4
When we say this is a strong argument, we do so against typical background assumptions like
these: Dr. Badesh is not likely to suddenly change his treatment preferences, and one case of the
flu is much like the others. Of course there might be an unexpected difference in case number 100,
but the very fact that a difference is unexpected attests to our thinking the argument is strong. The
argument could be much stronger if we made all the background assumptions explicit.
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What makes this an inductively weak argument, of course, is that the premises, if true, do not make the conclusion probable or likely to be true. In this
instance, the argument commits the familiar error of generalizing from a single
case. As the saying goes, one swallow does not make a summer. We should not
infer conclusions from too little evidence.
Moral Arguments
What we call a moral argument is an argument in support of a substantive
moral claim—that is, a claim about the moral status of acts, policies, persons,
and so forth. The following, for instance, are examples of substantive moral
claims: Euthanasia is morally permissible; progressive taxation is unjust; an
unrepentant serial murderer is evil. In the next chapter, we examine several
influential normative ethical theories. One of the principal aims of these theories, we shall see, is to provide correct, general principles that tell us what
makes actions (policies, and so forth) right and wrong, and persons good and
bad. As we’ll now explain, these principles can play an important role in arguing for substantive moral conclusions.
Consider the following simple argument:
(1) Active euthanasia minimizes overall suffering.
(2) Therefore, active euthanasia is morally right.
Notice that this argument is invalid: the premise, if true, does not guarantee
the truth of the conclusion. Although active euthanasia may well minimize
overall suffering, it does not logically follow that it is right. But now consider
the following moral principle:
Any act that minimizes overall suffering is morally right.
This principle tells us that minimizing overall suffering is a “right-making”
feature of actions; any action that has this feature is morally right. With this
principle in hand, we can now construct a deductively valid argument for our
conclusion:
(1) Any act that minimizes overall suffering is morally right.
(2) Active euthanasia minimizes overall suffering.
(3) Therefore, active euthanasia is morally right.
Notice the structure of this argument. Premise (1) tells us that any act that has
a certain property is morally right. Premise (2) tells us that a particular act has
this property. We can therefore validly conclude that the act in question is morally right. In this way, moral principles can be combined with relevant factual
premises to construct deductively valid arguments in support of substantive
moral claims.
Although we have been focusing on the role of moral principles in the
construction of deductively valid moral arguments, it is worth noting that our
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comments about the interplay between moral principles and relevant factual
claims apply also in the case of inductive arguments. Consider, for example,
the following argument:
(1) Usually, but not always, acts of dishonesty are wrong.
(2) By withholding relevant information, Dr. Badesh acted dishonestly
toward his patient.
(3) Therefore, it was wrong for Dr. Badesh to withhold relevant information
from his patient.
This argument is inductive. The premises, if true, are not intended to guarantee that the conclusion is true. Rather, the premises provided are intended
only to make the conclusion probably true. Still, the omission of either the
moral principle or the relevant factual claim would significantly weaken the
argument.
In summary, the general moral principles provided by normative ethical
theories can play an important role in arguing for substantive moral claims. As explained above, the moral principles,
when combined with relevant factual claims, can be used to
DISCUSSION
construct deductively valid or inductively strong arguments
Consider the following
for substantive moral views. We critically examine the moral
argument: Homosexuality
principles offered by leading normative ethical theories in the
is unnatural; therefore,
next chapter. First, however, we consider some useful methods
homosexuality is wrong.
for evaluating moral principles in particular, and philosophical
What is the missing premise?
claims in general. We also consider common fallacies to avoid
when constructing and evaluating arguments.
UP FOR
PHILOSOPHICAL METHODOLOGY—
COUNTEREXAMPLES AND THOUGHT
EXPERIMENTS
We mentioned earlier that philosophical views should be accepted or rejected
on the basis of the arguments offered in their support. If you disagree with an
author’s position on some issue, then you must believe that the author’s argument for that view is unsound or weak. So you must believe either that the
premises fail to adequately support the conclusion or that at least one premise
is false. Let’s now consider methods employed by philosophers to show that
a philosophical claim is false, or that the premises do not adequately support
the conclusion.
To evaluate or test philosophical claims and arguments, philosophers
often employ counterexamples and thought experiments. A counterexample
is just that—an example that counters a given claim or argument. A thought
experiment is a kind of mental experiment one performs through an exercise
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of imagination. Thought experiments are a very useful way to generate
counterexamples. To illustrate these methods, let’s return to an argument discussed earlier:
(1) Any act that minimizes overall suffering is morally right.
(2) Active euthanasia minimizes overall suffering.
(3) Therefore, active euthanasia is morally right.
We noted earlier that this argument is valid. If you disagree with the conclusion, you must therefore show that at least one of the premises of this argument is false.5 The first premise expresses the moral principle that any act that
minimizes overall suffering is morally right. But is that true? A good way to
test this claim is to see whether we can find a counterexample to it. That is,
we want to see whether can find an instance of an act that minimizes overall
suffering yet is not right. Engaging in a thought experiment will help us to
discover possible counterexamples. The task here is to see if we can imagine a
situation in which an act that minimizes overall suffering is not right. With a
little thought, it seems that we can in fact imagine many such situations. The
following paragraph presents one example.6
Suppose a boy from the neighbourhood knocks on my door one Saturday
morning and offers to mow my lawn for $20. My lawn needs mowing, and
I’m too busy to take care of it myself, so I agree. An hour later the boy knocks
on my door again to collect his money. I inspect the lawn and see that he has
done a very nice job. As I reach for my wallet to pay the boy, it occurs to me
that I could minimize overall suffering by donating the $20 I promised to pay
him to a local charity. Let’s suppose that I’m right: breaking my promise to
pay the boy and donating the money to a local charity really would minimize
overall suffering. In that case, premise (1) implies that breaking
my promise is the morally right thing to do. But our commonsense moral beliefs suggest that this is not the right thing to do.
DISCUSSION
And so we seem to have a counterexample to (1); we have an
Can you think of another
example of an action that minimizes overall suffering, yet does
counterexample to the claim
not appear to be morally right.
that “any act that minimizes
This counterexample provides us with good reason for
suffering is morally right”?
thinking that (1) is false, and that the above argument is
UP FOR
5
One could attack this argument by criticizing either premise (1) or (2). Since our present concern
is to explain how to test philosophical claims in general, and moral principles in particular, we
focus our attention on criticizing premise (1), and the moral principle that it contains. Premise (2)
does not contain a moral claim. It simply says that active euthanasia minimizes overall suffering.
Whether this is in fact true is an empirical matter, and can be evaluated through ordinary empirical
methods.
6
This example is based on an objection raised by Will Kymlicka in his Contemporary Political
Philosophy: An Introduction, 2nd ed. (Oxford: Oxford University Press, 2006), 24.
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therefore unsound. But remember, it doesn’t follow from this that the conclusion of the argument—that active euthanasia is permissible—is false.
One might wonder why this counterexample provides good reason for
thinking that the moral principle in question is false. After all, we seem to
have done little more than show that the moral principle in question conflicts with what you and I happen to believe is the right thing to do in the
example described. Perhaps, though, the principle is correct, and it is our
belief about what’s right that is mistaken. The more general question here is
how the use of counterexamples can show that any moral principle or theory
is false, if the counterexamples are simply based on our commonsense moral
beliefs. There is a great deal to be said about this topic that we cannot address
here. We shall have to limit ourselves to a brief discussion of the concept of
reflective equilibrium. This will help to shed some light on the legitimacy of
thought experiments and counterexamples when evaluating moral principles
and theories.
Reflective equilibrium, in the context of moral philosophy, is the end
point of a process of moral deliberation that involves going back and
forth between moral principles and what they imply about specific cases.
The ultimate goal of this process is to attain a state of coherence or consistency between the moral principles we accept and our considered moral
beliefs. We have achieved reflective equilibrium when we have achieved
this state of consistency. The basic process goes like this. If a principle or
theory has implications that conflict with our moral beliefs, and we have
a high degree of confidence in our moral beliefs, then we may reject or
revise the principle until we find one that matches our beliefs. However, if
a principle conflicts with our moral beliefs, but we lack confidence in these
beliefs, then we may want to revise or reject our beliefs to achieve a state of
consistency.
To illustrate, let’s return to the principle considered above: Any act that
minimizes overall suffering is morally right. We want to know whether this
principle is correct and deserves our acceptance. So we then consider what this
principle implies in specific cases. We saw earlier that this principle implies
that it would be morally right to refuse to pay the boy who mowed your lawn
and to give the money to a charity instead, for this would minimize overall
suffering. Upon reflection, however, most of us believe that it would be wrong
to give the money to the charity if that meant breaking the promise to pay the
boy. That is our considered belief or judgment about this case. Since we have
a high degree of confidence in this judgment—more confidence that this judgment is correct than that the principle is correct—we should revise or reject the
principle in question, and seek another that is consistent with our judgment. If
we lacked confidence in this judgment, however, then we might want to seek
consistency by revising or rejecting the judgment. The goal, again, is to attain a
consistent fit between our moral principles and moral judgments about cases.
And the fact that the moral principles we accept are in equilibrium with our
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considered moral judgments confers justification on both the principles and
the beliefs.7
One final point about thought experiments is in order before we turn
our attention to fallacies. Thought experiments often involve unusual and
unrealistic situations. But it is important to see the relevance of these examples. The force of the counterexample described does not depend on whether
the imagined example would ever actually happen, or whether it involves a
situation we might actually find ourselves in. The only constraint is that the
imagined situation is one that is logically (or conceptually)
possible. Notice that (1) asserts that any act that minimizes
Technique
overall suffering is morally right. Given this, it is perfectly
legitimate to test this claim by imagining situations that
As a matter of argumentative
may or may not be very realistic. It is very important to
strategy, it is sometimes wise to make
bear this point in mind as you read the debates, for you’ll
your counterexamples as realistic
as possible. People are sometimes
sometimes encounter strange counterexamples and thought
distracted and confused by fanciful
experiments that are used to test the authors’ (and others’)
fictional counterexamples, and thus
moral views.
fail to see their relevance.
COMMON FALLACIES
A fallacy is a mistake in reasoning. There are many different kinds of fallacies,
but we focus here only on a few of the more common errors in reasoning. We
begin with some fallacies that occur in developing arguments, and then turn
to some fallacies involving the misuse of language, and finally consider some
mistakes in reasoning that occur when people criticize arguments.8
Circularity (a.k.a. Begging the Question)
A circular argument is one in which the truth of the conclusion is presupposed
by one or more premises.9 The most blatant form of circularity occurs when
7
The method of testing moral principles against our considered beliefs is one that is both common
and widely accepted among moral philosophers. We recognize, however, that there is some
controversy about this method and about “coherence” accounts of justification, but discussion
of this controversy is well beyond the scope of this book. For an excellent discussion of reflective
equilibrium, see the Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/
reflective-equilibrium/.
8
For a more thorough discussion of fallacies, see the entry on fallacies in the Internet Encyclopedia
of Philosophy, http://www.iep.utm.edu/f/fallacy.htm.
9
An argument like “It is raining; therefore, it is raining,” is clearly circular. Note that it nonetheless
fits our earlier definition of an argument: “An argument is simply a set of at least two claims. One of
these is the conclusion, and any other claims are premises.” There is no requirement in the definition
that the premises all be distinct from the conclusion. In fact, circular arguments, though rarely useful,
are even valid, for it is not possible for their premises to be true while the conclusion is false.
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Theory
It is rather difficult to state the
problem of circularity in precise
terms, because all valid arguments
are circular in the sense that the
conclusion is logically “contained”
in the premises. Yet we certainly
don’t want to say that all valid
arguments are fallacious. So why
is circularity a problem in some
cases, but not others? To answer
this question, it may help to
consider a common reason for
giving an argument. The point is
often to convince others that your
conclusion is correct. It will not
help to convince others that your
conclusion is correct, however,
if you appeal to the conclusion
to help establish it. Circularity
is a problem, then, when the
conclusion you are arguing for
appears as one of your premises, or
is offered as a reason for accepting
one of your premises, and you
intend to convince someone of the
conclusion.
the conclusion you are arguing for appears as a premise
in your argument. Consider, for instance, the following
argument:
(1) Abortion is wrong.
(2) Therefore, abortion is wrong.
There are, however, less obvious cases of circularity, as illustrated by this example:
(1) Abortion is murder.
(2) Therefore, abortion is wrong.
This second example is simply a disguised version of the
conclusion, for “murder” simply means “wrongful killing.”
To make this point explicit, the argument could be more
clearly expressed as follows:
(1) Abortion is wrong.
(2) Abortion is killing.
(3) Therefore, abortion is wrong.
The circle in the argument is now apparent. The problem
with the circle is that we would not accept the premises of
this argument unless we already accepted the conclusion. So
if you are in doubt whether abortion is wrong, this argument
will do little to persuade you that it is wrong. Although circular arguments are generally uninformative and unpersuasive, notice that they are valid and may be sound.
UP
FOR
DISCUSSION
Is the following argument guilty of circularity?
Explain your answer.
False Dilemma
Presenting fewer options than are actually
available when arguing for a view is known
(1) The Bible is the inerrant word of God.
as the false dilemma fallacy. When attempt(2) The Bible says that God exists.
ing to garner support for his “war on terror,”
(3) Therefore, God exists.
for instance, former US President George
W. Bush (in)famously claimed: “Every nation, in every region, now has a decision to make. Either you are with us, or you are with the terrorists.”10 Faced
with just these two options, there is little choice except to side with the United
States. However, President Bush is guilty of presenting a false dilemma. There
were (and are), in fact, a number of positions nations can take aside from supporting President Bush’s “war on terror” or the terrorists themselves.
10
As reported by CNN, 6 November 2001, http://archives.cnn.com/2001/US/11/06/gen.attack.
on.terror/ (accessed 10 May 2009).
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Equivocation
There are a host of fallacies involving the manipulation of language in order to
attempt to support a conclusion. We will consider two of the more common of
these, beginning with the fallacy of equivocation.
An example of the fallacy or equivocation is the following:
(1) All humans have a right to life.
(2) My appendix is human.
(3) Therefore, my appendix has a right to life.
This argument is clearly invalid. The problem is that the word human is
ambiguous—that is, it has more than one meaning. It can mean a biological
classification (membership in the species Homo sapiens), and it can refer to
having moral status. Once this is realized, the fallacy of equivocation becomes
apparent. The term human is most clearly used to refer to moral status in the
first premise, and to biological status in the second premise. Once this is noted,
we can rewrite the argument without the ambiguous term, and the invalidity
of the argument reveals itself.
(1) It is wrong to kill those with moral status.
(2) My appendix is biologically human.
(3) Therefore, it is wrong to kill my appendix.
Now that the premises are clarified, we see that even if they are true, they
fail to prove the conclusion. As critical thinkers who are searching for the truth,
we need to try to spot equivocation. And we need to try to avoid falling into
the trap of committing this mistake when developing our own arguments.
Appeal to Emotion
Another fallacy involving the misuse of language is the appeal to emotion in
order to argue for some claim. Claiming that euthanasia and abortion ought to
be opposed because they’re murderous would be an instance of using inflammatory language in order to make one’s point. Of course, such claims not only
beg the question, but they also are often advanced so as to get the reader or
listener to accept the conclusion without having to think carefully about the
issues involved.
Straw Man
The straw man fallacy is the fallacy of misrepresenting your opponent’s argument so that it is easily shown to be unsound or weak. The fallacy is so named
because a straw man argument is easily blown down. Suppose, for instance,
that a philosopher offers the following argument in support of euthanasia:
(1) If competent, seriously disabled adults express a preference to die, then
they should be permitted to die.
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Chapter 1 Arguments and Methodology
(2) Some competent, seriously disabled adults do in fact express a preference
to die.
(3) Therefore, some competent, seriously disabled adults should be permitted
to die.
Now, suppose a critic objects as follows: “My opponent is claiming that we
should euthanize all disabled persons, since all disabled persons desire to die.
But it is not true that all disabled people want to die. So my opponent’s argument is clearly unsound.” This critic would be guilty of the straw man fallacy,
since he has misrepresented his opponent’s view to make it easier to refute. His
opponent’s actual position is much more subtle and less easily refuted than the
argument attributed to him.
Ad Hominem
Ad hominem is a Latin expression that means “against the man.” One commits
the ad hominem fallacy when one tries to refute an argument by attacking the
one who offered the argument. For example, suppose that a leader of an evangelical church presented the following argument in support of his “pro-life”
position on abortion:
(1) All human lives are sacred.
(2) Fetuses are human.
(3) Therefore, fetuses’ lives are sacred.
Now, imagine that a critic objects as follows: “We can safely reject this
argument, since it is being advocated by a religious extremist who believes
all sorts of crazy things!” This critic would be guilty of committing the ad
hominem fallacy, since he attempts to refute his opponent’s argument by
attacking his opponent. The only way to show that an argument fails is to
show that there is a problem with the argument itself.
Conclusion
There are, of course, many other fallacies that we cannot explain here.
What counts as a fallacy depends, moreover, on the context in which
an argument is offered and the intentions of the person offering it.
A full discussion would be very complex. The general point is that moral
philosophy—indeed, philosophy in general—is first and foremost a matter of searching for the truth through the careful use of reason. We want
to discover the truth by fairly and carefully considering the arguments
on all sides of an issue. Doing philosophy therefore requires a sense of
fairness, as well as a sharp, critical, and open mind. We want to arrive at
the truth, but we should accept a claim as true only if we are reasonably
confident that it is supported by a good argument.
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Arguments and Methodology Chapter 1
15
Review Questions
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What are the two features of a good argument?
What is a valid argument?
Construct your own example of a valid argument.
What is a sound argument?
What is an inductive argument?
What makes an inductive argument strong?
What is a moral argument?
What is a counterexample?
Describe an example that counters the following claim: Killing human
beings is always wrong.
What is reflective equilibrium?
Explain the fallacy of circularity.
Explain the straw man fallacy.
Explain the fallacy of equivocation.
Explain the fallacy of appeal to emotion.
Explain the ad hominem fallacy.
Explain the false dilemma fallacy.
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