When evaluating a conclusion, what is the most reliable indicator of an unstated assumption?

When evaluating a conclusion, what is the most reliable indicator of an unstated assumption?

• A. The author's motive.
• B. A claim that must be true if the conclusion is valid but is not explicitly stated.
• C. The length of the argument.
• D. A counterexample.

Answer: (B)

When evaluating a conclusion, the most reliable indicator of an unstated assumption is a claim that must be true for the conclusion to be valid but is not explicitly stated. This kind of premise is the hidden link that the argument relies on; without it, the conclusion could fail. If you can identify a statement that would have to hold true for the conclusion to hold, and that statement isn’t stated by the author, you’ve found the unstated assumption underpinning the reasoning. The other possibilities don’t serve this role as directly. The author’s motive might affect credibility but doesn’t specify what must be true for the conclusion to follow. The length of the argument offers no reliable insight into what is assumed. A counterexample challenges the conclusion itself rather than revealing the underlying premise that makes the conclusion possible.

When evaluating a conclusion, the most reliable indicator of an unstated assumption is a claim that must be true for the conclusion to be valid but is not explicitly stated. This kind of premise is the hidden link that the argument relies on; without it, the conclusion could fail. If you can identify a statement that would have to hold true for the conclusion to hold, and that statement isn’t stated by the author, you’ve found the unstated assumption underpinning the reasoning.

The other possibilities don’t serve this role as directly. The author’s motive might affect credibility but doesn’t specify what must be true for the conclusion to follow. The length of the argument offers no reliable insight into what is assumed. A counterexample challenges the conclusion itself rather than revealing the underlying premise that makes the conclusion possible.