Transcript Critical Thinking - Western Washington University

arguments
introduction
An argument is a series of statements,
one of which is offered as a statement to
be supported, and the rest of which are
offered as support.
 A conclusion is a statement to be
supported.
 A premise is a statement that offers
support.

arguments
arguments
The Benefits Argument. The Parents’
suggestion was based on the idea that,
because Theresa was going to die soon
anyway, her organs were doing her no good.
The other children, however, could benefit
from them. Thus, their reasoning seems to
have been: If we can benefit someone,
without harming anyone else, we ought to do
so. Transplanting the organs would benefit
the other children without harming Baby
Theresa. Therefore, we ought to transplant
the organs.
arguments
The Benefits Argument. The Parents’
suggestion was based on the idea that,
because Theresa was going to die soon
anyway, her organs were doing her no good.
The other children, however, could benefit
from them. Thus, their reasoning seems to
have been: If we can benefit someone,
without harming anyone else, we ought to do
so. Transplanting the organs would benefit
the other children without harming Baby
Theresa. Therefore, we ought to transplant
the organs.
arguments
If we can benefit someone, without
harming anyone else, we ought to do so.
2. Transplanting the organs would benefit
the other children without harming Baby
Theresa.
3. [Therefore] We ought to transplant the
organs.
1.
the benefits argument
A valid argument is one in which it is
impossible for the premises to be true
while the conclusion is false—i.e., if the
premises are true, then the conclusion
must be true as well.
 An invalid argument is one in which it is
possible for the premises to be true while
the conclusion is false.

validity
A sound argument is a valid argument
with all true premises.
 An unsound argument is an argument
that is either invalid or has a false
premise.

soundness

A fallacy is a bad argument with the
power to persuade.
fallacies

The fallacy of equivocation occurs
when someone uses the same word in
two different ways.
Equivocation
There are 365 days in the year, but the average
person only works 8 hours a day. That’s onethird of a 24-hour day. So the average person
only works the equivalent of one-third of 365
days—that is, about 122 days. However, the
average person doesn’t work on the weekends.
This means 2 days off a week. There are 52
weeks in a year, so there are 104 days off per
year. Subtracting this from 122 days leaves
only 18 days. But the average person gets at
least this many days off each year between
holidays and vacation time. So the average
person doesn’t work at all.
equivocation

A false dilemma is an argument that
presupposes there are only two options
on some issue, when in fact there are
more.
false dilemma
Our response [to 9/11] involves far more than instant
retaliation and isolated strikes. Americans should not
expect one battle, but a lengthy campaign, unlike
any other we have ever seen. It may include
dramatic strikes, visible on TV, and covert operations,
secret even in success. We will starve terrorists of
funding, turn them one against another, drive them
from place to place, until there is no refuge or no
rest. And we will pursue nations that provide aid or
safe haven to terrorism. Every nation, in every
region, now has a decision to make. Either you are
with us, or you are with the terrorists. (Applause.)
-G.W. Bush
false dilemma

A straw man is an argument that
attacks a misrepresentation of some
view and then concludes that the view is
false.
straw man
You have perhaps noted that global warming
has struck Washington, hard. Since Gore
behind talking about this nonsense, the
weather has gone cold all over North
America: We’ve had record storms in the
Midwest; we have a record low temperature
right now at Washington, D.C., for this time
of year. So, everything seems to be saying,
God seems to be saying “Gore is wrong!”
-Lyndon Larouche
straw man
Average GRE Scores by Intended Graduate Major, 7/1/01-6/30/04
VERBAL REASONING
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
PHILOSOPHY
English Lang. & Lit.
Humanities & Arts – other
History
Arts – History, Theory
Religion
Physics / Astronomy
Library/Archival Sciences
Anthropology/Archaeology
Foreign Lang. & Lit.
Political Science
Economics
Mathematics
Earth/Atmos./Marine Scs.
Engineering – Materials
QUANTITATIVE REASONING
589
559
558
543
538
538
534
533
532
529
522
504
502
495
494
1. Physics / Astronomy
738
2. Mathematics
733
3. Engineering – Materials
729
4. Engineering – Electrical
728
5. Engineering – Chemical
727
6. Engineering – Mechanical
723
7. Engineering – other
714
8. Engineering – Industrial
710
9. Business – Bank. & Fin.
709
10. Economics
706
11. Computer & Info. Sciences 704
12. Engineering – Civil
702
13. Chemistry
682
14. Earth/Atmos./Marine Scs. 637
15. PHILOSOPHY
636
who cares?
ANALYTICAL WRITING
1. PHILOSOPHY
2. English Lang. & Lit.
3. Arts & Humanities – other
4. History
5. Political Science
6. Religion
7. Anthropology/Archaeology
8. Arts – History, Theory
9. Education – Higher
10. Foreign Lang. & Lit.
11. Sociology
12. Communications
13. Economics
14. Education – Secondary
15. Library/Archival Sciences
5.1
4.9
4.8
4.8
4.8
4.8
4.7
4.7
4.6
4.6
4.6
4.5
4.5
4.5
4.5
Music: $35,900 / $55,000
 Nursing: $54,200 / $67,000
 Nutrition: $39,900 / $55,300
 Philosophy: $39,900 / $81,200

who cares?