2.2 Recognizing Arguments
REMINDER – For it to be an ARGUMENT,
1) at least one statement must claim to present evidence
2) there must be a claim that the evidence implies something
3) it can NOT be just a contradiction (recall the movie
)
An Argument
PREMISE(S)
CONCLUSION
Claimed (and
generally accepted
as ‘fact’) evidence
What is claimed
to follow from
the premises
Premise – A statement used in an argument which provides the
supposed “evidence” needed in order to support some other
statement which we are to supposed believe follows from the
premise (or premises)
Conclusion – The statement in an argument that the other
“factual” statement (or statements) claim to support and
provide evidence
We generally disclose the fact that we are arguing by using words
and phrases like ‘thus’, ‘since’, ‘hence’, ‘therefore’, ‘we see that,’
and so forth. These expressions are called illatives, and their
purpose is to show that someone is making an argument. Some
illatives (e.g., ‘thus’, ‘therefore’, and ‘it follows’) mark conclusions;
others (e.g., ‘since’, ‘as’, and ‘for the reason that’) mark premises.
Premise indicator words:
since (not temporal)
because*
in that
as
seeing that
inasmuch as
Conclusion indicator words:
therefore
accordingly
entails that
thus*
we may infer
for this reason
implies that
.
as indicated by
for
may be inferred from
given that
for the reason that
owing to
wherefore
we may conclude
hence
consequently
it must be that
it follows that
as a result
*Note: "Because" and "thus" can be used in both explanations and arguments.
While illatives (indicator words) often indicate that an
author is reasoning, they are not conclusive. Also, in
many arguments, there are. no indicator words; the
general context may disclose that the author is making
an argument. Here is an example:
In this passage, the first sentence expresses the
conclusion, and premises follow, but there are no
illatives (indicator words).
Sometimes it is just the meaning
. of the passage or its
setting (context) that indicates the presence of an
argument.
Whether or not to smoke is a conscious decision made in
the light of an abundance of information on the lethal
effects of tobacco. Surely those who choose unwisely
should bear the cost of any resulting ill health.
No illatives (premise-indicators or conclusion-indicators)
are used here, yet the argument is unmistakable.
That there was a racial imbalance in student attendance
was not tantamount to a showing
that the school district
.
was in noncompliance with its duties under the law.
Racial balance is not to be achieved for its own sake. It
is to be pursued when racial imbalance has been
caused by a constitutional violation. Once the racial
imbalance due to the de jure violation has been
remedied, the school district is under no duty to remedy
imbalance that is caused by demographic factors.
The first sentence of this passage presents the conclusion
of the argument, and the sentences that follow after it
offer the reasons (the evidence) for what has gone on
before the current imbalance.
Most arguments can be made plain by their contexts.
.
If I called from the office and said, “I’ll be bringing two
lobsters home for dinner,” you probably would not set
more places at the table but would instead make sure
that there was a large pot of boiling water on the stove
when I got there.
You might, however, have to think about it a little longer if I
just walked in from the barn and announced,
“The pig is ready to eat.”
Do you know if….
The pig is hungry or cooked?
Context can tell you a lot about arguments.
.
Also worth noting is that many arguments contain
additional material that is neither part of the conclusion
nor part of the premises.
Some of it is useless, but occasionally it can serve as
background material that can help the reader (or
listener) better understand what the argument is about.
If the criminal law forbids suicide, that is not an argument
valid in the Church, and besides, the prohibition is
ridiculous. For what penalty can frighten a person who
is not afraid of death?
All statements in an argument are supposed to be in
declarative form, but the premise
in the previous
.
argument was obviously a rhetorical question.
For what penalty can frighten a person who is not afraid of
death?
When a person asked a rhetorical question, she typically
assumes that everyone will answer it with some
inescapable answer. The answer to the “what penalty”
question is presumably “none.”
Thus, the rhetorical question could be re-written in a
declarative form as “There is no penalty that can frighten
a person more than death itself.”
Using rhetorical questions as either premises or
conclusions in an argument is risky (and should be
. is not always “obvious” to
avoided), because the answer
everyone.
If there is no one who desires to be miserable, there is no
one, Meno, who desires evil; for what is misery but the
desire and possession of evil?
When Socrates asked this question, was he correct in
assuming that misery is the desire and possession of
evil? The answer to the question is not obvious.
Because the answer is not always obvious, many people
(especially those in politics) like rhetorical questions for
that very reason!!!
Declarative
statements can
be said to be
either true or
false, but
rhetorical
questions have
no truth value
and so, for that
very reason, are
used to avoid
responsibility for
a forth-right
assertion of a
dubious claim.
.
A dubious claim
A former Secretary of Labor, opposing a later nominee for
the same post, asked in an. op-ed column in the New
York Times: “If she doesn’t believe the person working
for her was an employee, how vigorously will she protect
employees in general?”
Did the author assert that she, the nominee, would not
protect employees?
No, he didn’t ‘say’ that.
He might have implied it, but since he never actually ‘said’
it, we cannot know whether it is true or false that he
even believes that the nominee would not protect
employees. So his question becomes mere
meaningless political jargon.
If a right to euthanasia is grounded in self determination, it
cannot reasonably be limited to the terminally ill. If
.
people have a right to die, why must they wait until they
are actually dying before they are able to exercise that
right?
The implicit answer (there is no good reason, and
therefore the claim that “people need not wait until they
are actually dying before the are permitted to exercise
that right”) is assumed to be inescapable.
Arguments sometimes conclude with an imperative
(command) statement. Reasons
to perform a given act
.
are set forth, and we are then directed to act in that way.
In Hamlet, Polonius gives the famous argument in guiding
his son, Laertes:
Strictly speaking a command. (an imperative), like a
question, cannot be a statement in an argument
because it has no truth value.
But in many situations, it is useful to regard a command
(when it’s the conclusion of an argument) as no different
from a statement (or proposition).
In the previous examples, the conclusions could be written
as “You ought to be neither a lender nor a borrower” and
“Getting wisdom is what you should do.”
Most people will agree that assertions of this kind can be
true or false.
We seek to grasp the substance of what is being asserted,
to understand what claims are serving to support what
.
inferences, whatever their external forms.
Some needed reformulations are merely grammatical.
A proposition that functions as a premise may take the
form of a phrase, rather than a declarative sentence.
This is well illustrated in the following passage discussing
the possibility of extraterrestrial life.
Is there life beyond earth? The jury is still out. But with
(P1) planets aplenty; with (P2) creatures that can live
without the energy of a nearby star; with (P3) abundant
resources of cosmic hydrogen and oxygen to make water;
with (P4) several natural ways for planets to generate
internal heat; with (P5) the possibility that life could originate
in undersea volcanoes and propagate varieties hardy
enough to spread their seeds to other worlds; and with
(P6) rocky meteorites that could serve as vehicles for
interplanetary exchange; (C:) the idea that life has evolved
elsewhere in the universe seems less daunting than it did
just a few years ago.
There are six distinct premises (although not complete
statements), each of which calls attention to recently
discovered “facts” or at least “possibilities.”
Each could be rephrased as a declarative statement:
“There are plenty of planets.” “Many creatures can
live without the energy of a nearby star.” And so forth.
Unstated Statements: Enthymemes
Arguments become even more complicated when one or
more of their constituent propositions is not stated but
assumed to be understood.
This, by the way, is how we talk in “real life.”
A friend tells you, “It’s really sad that
Mary’s father had a heart attack. He
should have gone to see the doctor
more regularly.”
What premise is assumed but not stated?
.
The argument:
People who do not see the doctor regularly are more apt
to have heart attacks. (missing)
Mary’s father did not regularly see the doctor.
Therefore, Mary’s father was apt to (and did) have a
heart attack.
He would not take the crown;
Therefore, ‘tis certain he was. not ambitious.
(William Shakespeare, Julius Caesar, Act 3, scene 2)
The unstated (but plausible) statement is “One who would
not accept the crown must not have been ambitious.”
The effectiveness of an enthymeme depends upon
whether or not the hearer recognizes the missing and
can agree that missing statement is true.
Sometimes the arguer presupposes that the hearer will
know the missing statement is false: “If slavery is not
wrong, nothing is wrong.”
“If slavery is not wrong, nothing is wrong.”
.
It is of course wildly false to say that nothing is wrong, and
from that it follows that it is equally false to say that
slavery is wrong.
This was a clever argument used by Abraham Lincoln,
because everyone could think of something that he or
she regarded as “wrong.”
But what if the hearer thinks the missing statement is
false?
Then the claim (conclusion) of the argument is very much
in dispute, and if in dispute, the conclusion does not
necessarily follow – thus, the argument is invalid.
2.3 Arguments & Explanations
Compare these two passages:
(1) Lay up for yourselves treasures in heaven, where
neither moth nor rust consumes and where theives do
not break in and steal. For where your treasure is,
there will your heart be also. -- Matt. 7:19
(2) Therefore the name of the tower is Babel; because the
Lord did there confound the language of the earth. -Gen. 11:19
The first passage is an argument. How do you know that?
The second passage has indicator words (‘therefore’ &
‘because’), but is it an argument?
The second passage explains why the tower was called
Babel, because it was the .place where humankind,
formerly speaking one language, became confounded
by many languages.
The passage assumes that the reader knows the “fact” of
the name, and so the intention is to explain why (i.e., the
“because”) the name was given to the place.
Unlike arguments, explanations don’t prove anything
The “known thing” is a matter. of “fact,” and the explanation
is intended to show “why” the fact is true
EXPLANANDUM – the statement that describes an event
or phenomenon (such as the name of the tower); this is
the “accepted fact”
EXPLANANS – the statement or group of statements that
purport to do the explaining (such as “why” the tower is
called “Babel”); this is the “why”
Note: in Latin, “um” mean singular (one fact), and the “s”
means plural (the statements doing the explaining); this
might be helpful as a memory trick
ARGUMENT
Premises
accepted
facts
Claim to
prove
|
|
|
|
Conclusion
THAT
EXPLANATION
Explanans
Claim to
shed
light on
|
|
|
|
accepted
fact
Explanandum
WHY
The Challenger exploded after lift-off
.
because of a failed O-ring.
(explanandum)
(explanans)
Many explanations can be re-expressed as arguments.
Explanation:
The sky appears blue
(explanandum)
Because light rays from the sun are scattered by
…moisture particles in the air.
(explanans)
Argument:
Light rays from the sun are scattered……. (premise)
Therefore, the sky appears blue.
(conclusion)
Warning: “Because” can be in both arguments & explanations.
To distinguish explanations from arguments, identify the statement
that is either the explanandum or the conclusion (usually this is
the statement that precedes the
word ‘‘because’’). If this
.
statement describes an accepted matter of fact, and if the
remaining statements purport to shed light on this statement,
then the passage is an explanation.
This method works for practically all passages that are either
explanations or arguments (but not both).
Perhaps the greatest problem confronting the effort to distinguish
explanations from arguments lies in determining whether
something is an accepted matter of fact. Obviously what is
accepted by one person may not be accepted by another. Thus,
the effort often involves determining which person or group of
people the passage is directed to—the intended audience.
Sometimes the source of the passage (textbook, newspaper,
technical journal, etc.) will decide the issue.
If in doubt, ask, “Would this be an accepted that fact that people
would ordinarily know?” If you’re still not sure, treat it like an
argument. Am I convinced by the premises to believe this “fact”?
Exercise: Determine which of the following passages are
arguments and which are explanations.
.
1. Women tend to have higher pitched voices than men
because they have shorter vocal chords. Shorter vocal
chords vibrate at a higher frequency than longer ones.
2. Freedom of the press is the most important of our
constitutionally guaranteed freedoms. Without it, our
other freedoms would be immediately threatened.
Furthermore, it provides the fulcrum for the
advancement of new freedoms.
3. Water is a good solvent for many different substances,
and it picks them up as it moves through the
environment. Thus, rain water flowing over and under
the ground dissolves minerals such as limestone.
4. If the earth’s magnetic field disappears, then the Van
Allen radiation belt will be destroyed. If the Van Allen
radiation belt is destroyed,.then intense cosmic rays will
bombard the earth. Therefore, if the earth’s magnetic
field disappears, then intense cosmic rays will bombard
the earth.
5. Five college students who were accused of sneaking
into the Cincinnati Zoo and trying to ride the camels
pleaded no contest to criminal trespass yesterday. The
students scaled a fence to get into the zoo and then
climbed another fence to get into the camel pit before
security officials caught them, zoo officials said.
6. Mortality rates for women undergoing early abortions,
where the procedure is legal, appear to be as low as or
lower than the rates for normal childbirth. Consequently,
any interest of the state in protecting the woman from an
inherently hazardous procedure, except when it would
be equally dangerous for her to forgo it, has largely
disappeared.
8.7 Disjunctive & Hypothetical
Syllogisms
A syllogism is a short argument that contains two
premises and a conclusion.
A disjunctive (or alternative) syllogism contains a
disjunctive statement as one of its premises.
Consider this disjunctive syllogism:
Either she was driven by stupidity or by arrogance.
She was not driven by stupidity.
Thus, she was driven by arrogance.
The two components of a disjunctive (“or”) statement are
called the “disjuncts.” So the
. two disjuncts in the
previous example are:
Either she was driven by stupidity or she was driven by
arrogance
Because the sentence has a compound predicate and a
single subject, the “she was” is part of both disjuncts
A disjunctive statement in Logic (unlike in real life) does
not assume one disjunct is true and the other one is
false; it merely assumes one is true; in fact, both may be
true (which is why Logic has an “inclusive ‘or’ ”
In a disjunctive syllogism, one premise is a disjuctive
statement and another premise
. denies the truth of one
of the disjuncts in the disjunctive statement.
The conclusion is the remaining disjunct.
Example:
or
You can eat either the orange or the apple.
You can’t eat the orange.
not
Therefore, you can eat the apple.
In Logic, the tilde (~) means “not” or “it’s false that,” and
the wedge (\/) means “or.”
This pattern is the general “rule” for a
disjunctive
syllogism. It says,
.
P1: Either Circle or Square
P2: Not Circle
C: Therefore, Square.
Anything can go inside the shapes. The Circle could stand
for “no fish in the sea” and the Square could stand for
“no fish in the air.”
Thus the disjunctive syllogism would be:
P1: Either there are no fish in the sea or no fish in the air.
P2: It’s false that there are no fish in the sea.
C: Therefore, there are no fish in the air.
Either
there are
No fish in
the sea
No fish in
the sea
\/
No fish in
the air
Read as:
It is false that there are
are no fish in the sea =
fish are in the sea
~
______________
No fish in
the air
Either
Smith is
not in New
York
Smith is
not in New
York
\/
Smith is
not in
Paris
Read as:
It is false that Smith is
not in New York =
Smith is in New York
~
______________
Smith is
not in
Paris
Since Smith IS in
New York, he cannot
be in Paris
The second type of most common syllogism is one in
which one or more of the three statements is a
.
conditional statement.
The one you probably know from math is the one called a
Hypothetical Syllogism in which all the statements (both
premises and the conclusion) are conditional
statements.
In a syllogism, the order of the premises does not matter.
If “X” is a man, then “X” will die.
B -> C
If Socrates is an “X,” then Socrates is a man.
A -> B
Therefore, if Socrates is an “X,” then Socrates will die. A -> C
A
B
B
C
.
.
A
C
.
 MP VALID
VALID MT 
 AC – fallacy
Together, AC and DA have over the years
acquired the name of MODUS MORONS –
fallacy
– DA these two fallacies!!!
in other words,
avoid
I go to Publix
.
I will spend money
I go to Publix
I will spend money
Modus Ponens (MP)
I go to Publix
I will spend money
I will spend money
I go to Publix
Modus Tollens (MT)
“Modus Morons” versions:
.
Affirming the Consequent (AC):
If I go to Publix, then I will spend money.
I will spend money.
Therefore, I will go to Publix.
The fallacy: I can spend money at LOTS of places besides
Publix!!!
Denying the Antecedent (DA):
If I go to Publix, then I will spend money.
I will not go to Publix.
Therefore, I will not spend money.
The fallacy: Similar to that above; even if I do not go to
Publix, that is no guarantee that I will not spend money!
Exercises. Pages 293-297
.