GMAT essay Lesson 5- Analysis of Argument (III)

3. The Insufficient Sample Fallacy
The Fallacy of the Insufficient Sample is committed whenever an inadequate sample is used to justify the conclusion drawn.

Here's an argument that commits the fallacy of the insufficient sample:

I have worked with 3 people from New York City and found them to be obnoxious, pushy and rude. It is obvious that people from New York City have a bad attitude.

The data for the inference in this argument are insufficient to support the conclusion. Three observations of people are not sufficient to support a conclusion about 10 million.

4. Ad hominen
One of the most often-employed fallacies, ad hominen means "to the man" and indicates an attack that is made upon a person rather than upon the statements that person has made. An
example is: "Don't listen to my opponent, he's a homosexual."

5. The Fallacy of Faulty Analogy
Reasoning by analogy functions by comparing two similar things. Because they are alike in various ways, the fallacy is that it is likely they will share another trait as well. Faulty Analogy arguments draw similarities between the things compared that are not relevant to the characteristic being inferred in the conclusion.

Here's an example of a Faulty Analogy fallacy:

Ted and Jim excel at both football and basketball. Since Ted is also a track star, it is likely that Jim also excels at track.

In this example, numerous similarities between Ted and Jim are taken as the basis for the inference that they share additional traits.

6. Straw Man
Here the speaker attributes an argument to an opponent that does not represent the opponent's true position. For instance, a political candidate might charge that his opponent "wants
to let all prisoners go free," when in fact his opponent simply favors a highly limited furlough system. The person is portrayed as someone that they are not.

7. The "After This, Therefore, Because of This" Fallacy (Post hoc ergo propter hoc) This is a "false cause" fallacy in which something is associated with something else because
of mere proximity of time. One often encounters - in news stories- people assuming that because one thing happened after another, the first caused it, as with "I touched a toad, I have a wart, the
toad caused the wart." The error in arguments that commit this fallacy is that their conclusions are causal claims that are not sufficiently substantiated by the evidence.

Here are two examples of the After This, Therefore Because of This Fallacy:

Ten minutes after walking into the auditorium, I began to feel sick to my stomach. There must have been something in the air in that building that caused my nausea.

The stock market declined shortly after the election of the president, thus indicating the lack of confidence the business community has in the new administration.

In the first example, a causal connection is posited between two events simply on the basis of one occurring before the other. Without further evidence to support it, the causal claim based on
the correlation is premature.

The second example is typical of modern news reporting. The only evidence offered in this argument to support the implicit causal claim that the decline in the stock market was caused by
the election of the president is the fact that election preceded the decline. While this may have been a causal factor in the decline of the stock market, to argue that it is the cause without additional information and auxiliary hypotheses that make a causal connection plausible is to commit the After This, Therefore, Because of This Fallacy.

8. The Either-or Thinking
This is the so-called black-or-white fallacy. Essentially, it says "Either you believe what I'm saying or you must believe exactly the opposite." Here is an example of the black-or-white
fallacy: Since you don't believe that the earth is teetering on the edge of destruction, you must believe that pollution and other adverse effects that man has on the environment are of no concern whatsoever.

The argument above assumes that there are only two possible alternatives open to us. There is no room for a middle ground.

9. The "All Things are Equal" Fallacy
This fallacy is committed when it is assumed without justification that background conditions have remained the same at different times/locations. In most instances this is an unwarranted assumption for the simple reason that things rarely remain the same over extended periods of time, and things rarely remain the same from place to place.

The last Democrat winner of the New Hampshire primary won the general election. This year, the winner of the New Hampshire primary will win the general election.

The assumption operative in this argument is that nothing has changed since the last primary. No evidence or justification is offered for this assumption.

10. The Fallacy of Equivocation
The Fallacy of Equivocation occurs when a word or phrase that has more than one meaning is employed in different meanings throughout the argument.

11. Non Sequitor
This means "does not follow," which is short for: the conclusion does not follow from the premise. To say, "The house is white; therefore it must be big" is an example. It may be a big house but there is no intrinsic connection with its being white.

12. Argumentum ad populum
A group of kindergartners are studying a frog, trying to determine its sex. "I wonder if it's a boy frog or a girl frog," says one student. "I know how we can tell!" pipes up another. "All right,
how?" asks the teacher, resigned to the worst. Beams the child: "We can vote." This is argumentum ad populum, the belief that truth can be determined by more or less putting it
to a vote. Democracy is a very nice thing, but it doesn't determine truth. Polls are good for telling you what people think, not whether those thoughts are correct. We are constantly bombarded with

ad populum arguments. Often they simply reflect careful wording. Ask people if they want cleaner air and they'll say sure, who doesn't? Ask if they want cleaner air that will be imperceptibly
cleaner to all except the most accurate instruments and say that you'll have to raise their gasoline prices to do it and you're going to lose a lot of those yeses. But the worst thing about ad populum
arguments is that they assume expertise where it simply cannot be assumed. You don't need expertise to show that cleaner air is in general a good idea. You do need expertise to determine
that making the air cleaner than it has already been made is good public policy in light of numerous conflicting considerations and that certain ways of getting the air cleaner are better than
others on the edge of destruction, you must believe that pollution and other adverse effects that man has on the environment are of no concern whatsoever."

13. Irrational appeals
These urge us to accept ideas at face value or on some basis other than their reasonableness. In effect, they say, "You don't have to think about this, there is no danger of error here." Included in false appeals are appeals to common sense, appeals to emotion, and appeals to authority. All such appeals are not necessarily irrational. They may, indeed, encourage critical thinking. But if used in the sense that they should be considered in a vacuum, then they are fallacious.