Logical ReasoningDifficulty: Hard

PT105 S2 Q21 Explanation

Some people have been promoting

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsMethod

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Stimulus

Some people have been promoting a new herbal mixture as a remedy for the common cold. The mixture contains, among other things, extracts of the plants purple coneflower and goldenseal. A cold sufferer, skeptical of the claim that the mixture is an effective cold remedy, argued, “Suppose that the mixture were an people who have colds but do not use the mixture, it is obviously not effective.”

What this question is testing

Method

Your task

Describe how the argument proceeds — the technique it uses to reach its conclusion.

Common trap

Answers that describe a method the argument doesn't actually use.

Winning move

Track the role each statement plays, then match that to the choice describing the same moves.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
21.

Which one of the following most accurately describes the method of reasoning the cold sufferer uses to reach the

Answer choices

  1. Correct63% picked this

    finding a claim to be false on the grounds that it would if true have

    Why this is right

    "Doing X on the grounds that Y" means that X is the conclusion and Y is the evidence. Does the conclusion find a claim to be false? Sure, it finds the claim [this herbal remedy is effective] to be false, because it concludes the mixture is not effective. Is the evidence saying that this claim, if true, would have consequences that are false? Yes, the evidence says that if it were true that the mix were an effective cold remedy then a consequence would be almost everybody with a cold would be using it but that consequence is false many people w/ colds do not use the mixture

    Skill tested: Method · how this choice captures the argument's function is the move to repeat next time.

  2. Bad Conclusion/Evidence Match7% picked this

    accepting a claim on the basis of public opinion of

    "Doing X on the basis of Y" means that X is the conclusion and Y is the evidence. Did the conclusion accept a claim? Nope, it rejected a claim, the claim that "this herbal mix is effective". If we wanted to play along with this answer, we could say that the author's conclusion is accepting the claim "this mixture is not effective". In that case, the evidence would have to be public opinion on whether "this mixture is not effective". But the evidence is not saying, "people don't think this mix is effective". The author isn't citing their opinion; he's only citing their behavior (whether many people do or don't currently use this remedy).

  3. Opposite: are met13% picked this

    showing that conditions necessary to establish the truth of a claim

    The author is showing that conditions (almost everyone is using the remedy) which are necessary to establish the truth of a claim (this remedy is effective) are not being met. In saying, "Suppose the mix would effective, it follows that almost everybody would be using it" would be diagrammed like this: mixture effective → almost everyone using it (claim) (necessary condition)

  4. Bad Conclusion / Evidence Match15% picked this

    basing a generalization on a representative group

    "Basing X on Y" means that X is the conclusion and Y is the evidence. Was the conclusion a generalization? Nope, it was a specific claim about this cold remedy: "It is obviously not effective" Is the evidence a representative group of instances? No, it's a hypothetical, followed by a hypothetical consequence, followed by an observation about the world in which we live in. There's no "representative sample" appealed to.

  5. Bad Conclusion Match2% picked this

    showing that a measure claimed to be effective in achieving a certain effect would actually make achieving

    The thing the author is showing in an argument is her conclusion. Was this conclusion saying that the cold remedy not only is ineffective at getting rid of your cold, it actually makes it harder to get rid of your cold? No, the conclusion only says the remedy is ineffective, not that it makes the situation worse.

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