IntroductionIntroductionarguments

ArgumentsArguments

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.

A deductive argument in one in which the premises are supposed to make the conclusion certain.

An inductive argument is one in which the premises are supposed to make the conclusion probable (without making it certain).

ArgumentsArguments

ValidityValidity

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.

SoundnessSoundness

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.

FallaciesFallacies

A fallacy is a bad argument with the power to persuade.

EquivocationEquivocation

The fallacy of equivocation occurs when someone uses the same word in two different ways.

EquivocationEquivocation

There are 365 days in the year, but the average person only works 8 hours a day. That’s one-third 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.

False DilemmaFalse Dilemma

A false dilemma is an argument that presupposes there are only two options on some issue, when in fact there are more.

False DilemmaFalse 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

Straw ManStraw Man

A straw man is an argument that attacks a misrepresentation of some view and then concludes that the view is false.

Straw ManStraw 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 say, God seems to be saying “Gore is wrong!”

-Lyndon Larouche

Who Cares?Who Cares?

Many 17-year-olds do not possess the 'higher-order' intellectual skills we should expect of them. Nearly 40 percent cannot draw inferences from written material; only one-fifth can write a persuasive essay; and only one-third can solve a mathematics problem requiring several steps.

-A Nation at RiskThe National Commission on Excellence in

Education

Who Cares?Who Cares?

Average GRE Scores by Intended Graduate Major, 7/1/01-6/30/04                VERBAL REASONING                                   QUANTITATIVE REASONING                               ANALYTICAL WRITING             1.  PHILOSOPHY                    589              1.  Physics / Astronomy             738               1.  PHILOSOPHY                         5.1 2.  English Lang. & Lit.               559              2.  Mathematics                         733               2.  English Lang. & Lit.                    4.9 3.  Humanities & Arts – other     558              3.  Engineering – Materials         729               3.  Arts & Humanities – other          4.8  4.  History                                  543              4.  Engineering – Electrical         728               4.  History                                       4.8 5.  Arts – History, Theory           538             5.  Engineering – Chemical          727               5.  Political Science                         4.8  6.  Religion                                 538             6.  Engineering – Mechanical       723               6.  Religion                                      4.8 7.  Physics / Astronomy              534             7.  Engineering – other                714               7.  Anthropology/Archaeology         4.7 8.  Library/Archival Sciences      533             8.  Engineering – Industrial           710               8.  Arts – History, Theory               4.7 9.  Anthropology/Archaeology    532             9.  Business – Bank. & Fin.         709               9.  Education – Higher                    4.610. Foreign Lang. & Lit.              529            10.  Economics                            706              10.  Foreign Lang. & Lit.                 4.611. Political Science                     522            11.  Computer & Info. Sciences   704              11.  Sociology                                 4.6  12. Economics                             504            12.  Engineering – Civil                702              12.  Communications                       4.513. Mathematics                          502            13.  Chemistry                             682              13.  Economics                                4.514. Earth/Atmos./Marine Scs.      495            14.   Earth/Atmos./Marine Scs.    637              14.  Education – Secondary             4.515. Engineering – Materials          494            15.  PHILOSOPHY                    636              15.  Library/Archival Sciences         4.5