Activity description

Faulty reasoning

The following statements rely on faulty reasoning. Can you explain why?

Example 1

1. Presents two options when other options exist.
2. Relies on the threat of force to persuade.
3. I don't know, tell me.

Feedback

The correct answer is (1).

This statement contains the false assumption that only two options exist. This is a fallacy of inference.
A fallacy of inference relies on flawed evidence to support an unwarranted assertion.

Example 2

1. Asks a rhetorical question.
2. Presents a personal attack.
3. I don't know, tell me.

Feedback

The correct answer is (2).

This statement attempts to discredit the person presenting the argument rather than the argument itself. This is a fallacy of motive.

A fallacy of motive appeals to desire, fear, or pity in order to persuade. Critical thinkers should focus their analysis on the argument, not in the person presenting it.

Example 3

1. Option 1: Inconsistently applies a key term.
2. Option 2: Relies on irrelevant evidence.
3. I don't know, tell me.

Feedback

The correct answer is (1).

This statement contains vague terms which are not defined consistently, in this case the word "right." This is a fallacy of ambiguity.

In a fallacy of ambiguity the argument has more than one interpretation. Sometimes this is used deliberately as a means to mislead and persuade.

Example 4

1. Compares two items that are not alike in relevant respects.
2. Assumes a single action will lead to a series of undesirable consequences.
3. I don't know, tell me

Feedback

The correct answer is (1).

This statement relies on irrelevant evidence to support an assertion.  This is a fallacy of relevance.

A fallacy of relevance appeals to irrelevant information that does not relate directly to the assertion being made.

Example 5

"My first child slept through the night but the second is a light sleeper. Therefore, first-born children sleep better than their siblings."

1. Assumes a causal relationship between two events. 
2. Applies the traits of a small group to a large group.
3. I don't know, tell me

Feedback

The correct answer is (2).

This statement assumes the properties of a small sample population are also true of a general population. This is a fallacy of induction.

A fallacy of induction means the conclusion is based on a mistaken inference, such as in a false analogy, or hasty generalization.

Example 6

1. Puts forward an assertion that does not follow from the evidence.
2. Assumes a causal relationship between two events. [ Correct ]
3. I don't know, tell me

Feedback

The correct answer is (2).

In this statement the pattern observed could be coincidental or caused by an unidentified cause.  This is a fallacy of false causation.

A fallacy of false causation observes a false relationship linking a sequence of events or trends.

Conclusion

How did you do?

Many arguments are persuasive but, as you have seen, there are many ways the reasoning behind them may be "faulty".

Some rely on unjustified hidden assumptions, or appeal to emotions rather than logic to persuade. Others use vague terminology, or cite irrelevant evidence. Others compare things that are not alike, or falsely relate events or trends.

Always be alert to this as you evaluate the strength of an argument!

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