Page 479 - Wordsmith A Guide to College Writing

Logos (low-gahse or low-gohse), or logic, according to Aristotle, is the
final element in argument or persuasion. The Greek word logos is at

the root of English words such as logic and logical. Logic is extremely

important in making an argument or persuading an audience. No

matter how strong the other elements of your writing are, they will

count for nothing if your argument does not make sense.

Signs of Flawed Logic in Argument

Here are some danger signs that may signal flawed logic:

Painting with too broad a brush. If you say “Older people are

usually bad drivers because their reflexes have slowed and their

reaction time is poor,” you are generalizing, or painting an entire group

of people with a single brushstroke. On the one hand, words such as
usually, never, and always increase your responsibility to make sure

that what you are saying is absolutely accurate. On the other hand,

words such as often, can, and may allow you to make a point without

using too broad a brush. Saying “Older drivers may lose their ability to

react quickly as they age” is much more realistic.

Staying on the surface. If you find yourself repeating generalizations

instead of analyzing, providing strong support, and giving examples,

your argument is a surface argument.

Making exaggerated claims. Have you seen ads that make claims
like this?