# LSAT Logical Reasoning: Flaw Questions

A “flaw” question is one that asks you to identify the how an argument’s reasoning is flawed. The question stem for a flaw question might read:

• The reasoning in the argument above is flawed in that it
• The reasoning in the _____’s argument is most vulnerable to criticism on the grounds that
• The argument is most vulnerable to criticism on the grounds that it fails to consider the possibility that

We solve these questions by following four steps:

1. Identify the argument’s conclusion.
2. Identify how the conclusion is supported.
3. If possible, identify any flaws in reasoning
4. Choose the answer that accurately describes how argument’s reasoning is flawed.

Let’s take a look at each step.

## Identify the Conclusion

The main conclusion of the argument is supported by everything else in the argument; it’s what the rest of the argument is attempting to convince you is true. If you struggle with identifying conclusions, take a look at the Identify the Conclusion Questions lesson.

## Identify How the Conclusion is Supported

Make a note of the premises. What supports the conclusion? Why does the author think we should believe the conclusion? Silently paraphrase the support to yourself, trying to understand why the author finds the premises to be so convincing.

## If Possible, Identify Any Flaws in Reasoning

Often test-takers can identify logical flaws before looking at answer choices. If you can do this, great! But even if you doubt your ability to spot a logical flaw, still take a moment to consider what might be wrong with the argument. The real point of this step is not to infer the answer in advance; the point is to think critically about the argument so that you can identify the correct flaw once presented with it.

The correct answer for a flaw question will meet two criteria:

1. The answer will accurately describe the argument.
2. The answer will point out flawed reasoning.

Begin with criterion 1. Often, this criterion is enough to eliminate every incorrect answer. And it almost always narrows down the answer choices significantly. Consider the following question as an example:

```I am always right. I know this because I said once that I am always right. And what I said must have been correct because I am the one who said it.
The argument is flawed in which of the following ways?

A. It mistakes mere correlation for causation.
B. It takes for granted that all people who were correct once must always be correct.
C. It overlooks the possibility that some people might not always be correct.
D. It treats what is necessary to produce a certain result as something that is sufficient to produce a certain result.
E. It assumes what it seeks to establish.```

### Applying Criterion 1

Most of the answer choices in this question can be eliminated just by considering which answers accurately describe the reasoning (criterion 1 above). Let’s look at each answer choice.

#### A. It mistakes mere correlation for causation.

The argument never implies that anything caused anything else. And there’s no correlation in this argument. This does not describe our argument.

#### B. It takes for granted that all people who were correct once must always be correct.

The argument does not take this for granted. At no pint is it implied that all people who were once correct must always be correct. The argument only talks about the author of the argument.

#### C. It overlooks the possibility that some people might not always be correct.

The argument never considers this possibility, so answer C does accurately describe the argument!

#### D. It treats what is necessary to produce a certain result as something that is sufficient to produce a certain result.

Nothing in this argument is “necessary to produce a certain result.” This just does not happen in the argument.

#### E. It assumes what it seeks to establish.

This does happen in the argument! The argument concludes “I am always right.” But it also assumes this statement to support it’s conclusion.

### Applying Criterion 2

So just by applying criterion 1, we’ve narrowed our answer down to two options. Let’s look at those two now and apply criterion 2.

#### C. It overlooks the possibility that some people might not always be correct.

This is not really problematic for our argument. Why would the argument need to consider this possibility? The fact that some people might not always be correct has little impact on whether or not one person in particular is always correct. So although the argument does overlook this possibility, no flaw has taken place here. An argument only needs to consider points that are relevant to its reasoning.

#### E. It assumes what it seeks to establish.

This is flawed reasoning. Assuming what you seek to establish is called “circular reasoning” and it’s not good logic. You could infer anything by using circular logic, even (as the above argument demonstrates) that you are always right. Thus, this is the correct answer.