LSAT 14 - Section 4 - Question 13

This is a necessary assumption question because the stem tells us that the argument is “depends” of the which of the offered “assumption.”

Necessary assumption questions fall under the subset of strengthen questions. All of the things we learned for strengthen, SA, and PSA question are still very important here! We’re going to be analyzing the stimulus the same way: identify the premise and conclusion, evaluate the argument, determine what, if anything, is missing. Our approach to the questions is very different. For NA question, in order for our conclusion to be true, our correct answer must be true. Without the correct answer, our argument will fall apart. This is what we’re looking for in our answer choice. Remember, we can always test our answer choices by using the negation test: if we negate the answer choice and it destroys our argument, its the correct answer!

This first sentence gives us the definition for addiction and, interestingly, the author uses “has been defined as” which kind of gives us the sense that this may be other people’s definition. This definition is that addiction means the dependence on and abuse of a certain substance. If we read onto the next sentence, even if the “however” is at the end, we can infer that the author does not agree with the running definition of addiction; he says that abuse and dependence do occur together.

The next two sentences are examples of this. He says cancer patients are dependent on morphine, but do not abuse it because they use it for their pain. And then he gives a general example of the reverse: a person can abuse morphine but does not need to dependent on it for anything.

Then we see our conclusion, which we predicted above: this definition of addiction is not correct.

This argument is fine. The salient feature of difficult NA question is that the correct answer choice can be VERY subtle. The negation test will be helpful for these answer choices.

Answer Choice (A) This is not necessary to our argument. Cancer patients could have abused morphine is the past; the argument allows for this! The example in the argument is a hypothetical that can occur. And if we negate the answer choice (cancer patients sometimes abuse morphine), this is completely compatible with the argument because the example with the cancer patient is a hypothetical.

Answer Choice (B) This is not necessary for the argument. This answer choice is trying to draw a distinction between the hypothetical language of the argument and what will happen. However, it is not necessary for all cancer patients to often become dependent on morphine. Similar to what we said in AC (A), cancer patients rarely (instead of often) becoming dependent to morphine and the rest never becoming dependent is compatible with the argument.

Correct Answer Choice (C) When we read the argument, we just assumed that we were obviously talking about cancer patients who were addicted to morphine. But, we did not explicitly say that. If we negate this answer choice, it destroys our argument because the example we give to lend support to our argument becomes useless if the cancer patients are not addicted. In other words, if the individuals discussed in our examples are just dependent on or abusing a substance and not addicted, our argument falls apart. Very subtle!

Answer Choice (D) Similar to (A) and (B), this is not necessary for the argument. It could be the case that some cancer patients are just abusing the drug without being dependent on it. The negation of this doesn’t destroy our argument.

Answer Choice (E) This would weaken our argument; we’re trying to prove that abuse and dependence can happen separately while being addicted.