LSAT Question Stem

Which one of the following principles, if valid, most strongly supports the researcher's reasoning? 

Logical Reasoning Question Type

This is a Principle question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The dental researcher presents the following premises and conclusion:

Premise 1: Filling a cavity in a tooth inevitably damages some of the healthy parts of the tooth.

Premise 2: Cavities are harmful only if the decay reaches the nerves inside the tooth.

Premise 3: Many cavities, if left untreated, never progress to the point where the decay reaches the nerves.

Conclusion: Dentists should not fill a cavity unless the nerves inside the tooth are in imminent danger from that cavity.

The structure of the argument is based on weighing the potential harm of filling a cavity against the potential harm of leaving it untreated. The researcher argues that since filling a cavity always causes some damage, and many untreated cavities never become harmful, it is better to only fill cavities when the nerves inside the tooth are in imminent danger.

An "Evaluate" question for this argument could be: "Can dentists accurately determine when the nerves inside a tooth are in imminent danger from a cavity?"

Now, let's discuss the question type and the answer choices. This is a Principle question, which asks us to identify the principle that most strongly supports the researcher's reasoning.

a) This answer choice suggests that dentists should perform procedures that are likely to be beneficial in the long term, but only if they do not cause immediate damage. While this principle is somewhat related to the argument, it doesn't directly address the issue of potential harm versus definite harm, which is the core of the researcher's reasoning.

b) This answer choice focuses on cavity prevention rather than the treatment of existing cavities. It does not address the researcher's argument about when to fill a cavity, so it is not the correct answer.

c) This answer choice states that a condition that is only potentially harmful should not be treated using a method that is definitely harmful. This principle directly supports the researcher's reasoning by providing a guideline for when to fill a cavity based on the potential harm versus definite harm. This is the correct answer.

d) This answer choice focuses on the progression of a condition and the temporary relief provided by certain treatments. It does not address the researcher's argument about the potential harm of filling a cavity versus leaving it untreated, so it is not the correct answer.

e) This answer choice suggests that a potentially harmful condition should not be left untreated unless it can be kept under constant surveillance. While this principle may be relevant to some situations, it does not directly support the researcher's argument about filling cavities based on the potential harm versus definite harm.

In conclusion, the correct answer is C, as it provides a principle that directly supports the researcher's reasoning by addressing the issue of potential harm versus definite harm in treating cavities.