Logical Reasoning

PT107 · S3 · Q10 The only motives that influence

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The only motives that influence all human actions arise from self-interest.

Conclusion

Self-interest is the chief (#1) influence on human action.

Evidence

The only motives that influence all human actions arise from self-interest.

Evaluation

Both the premise and the conclusion are about "self-interest" and "human action" and "influence", so we should subtract the commonality and focus on the variation.

If X is the only thing that's part of every action, does that mean that it's the #1 influence on action?

Does "most omnipresent = #1 influence"?

Maybe. But maybe love is a motive that influences only 98% of human actions, but when it's present, it has a stronger influence than self-interest.

Goal

Point out the language shift from "most omnipresent" to "most influential" or raise the possibility of a counterexample such as love, which may not influence 100% of human actions but still might end up being the #1 influence on human action.

10.

The reasoning in the argument is fallacious because the argument

  1. denies that an observation that

    Bad Conclusion Match

    This answer is saying that an observation was made that a certain trait is common to all the events in a pattern (the trait of self-interest is common to all the events in the pattern of human action), and then that the author denies that this can contribute to a causal explanation of human action. The conclusion almost does the opposite. The author certainly doesn't deny this observation, since it's her premise. And by calling this trait the chief influence it seems like she thinks that the observation can contribute to a causal explanation.

    3% picked this

  2. Correct

    takes the occurrence of one

    Why this is right

    Any time an answer is structured "Takes X as showing that Y", we would want X to match the Evidence and Y to match the Conclusion. Did the evidence talk about the occurrence of one particular influence on a pattern/class of events? Sure. She said that "self-interest" is particular influence on the class of "human actions" that "occurs in every case". Did the conclusion say that the influence of "self interest" outweighs any other influence? Yes. She said that it is the chief influence on human action. The "chief" outranks everyone else in the tribe. The chief influence is the #1 influence. Since the answer matches, we know it's right.

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

    67% picked this

  3. concludes that a characteristic of

    Wrong Flaw

    This answer choice describes a Temporal Flaw or Sampling flaw, in which the author assumes that "if it was true before / true here, then it will be true again / true everywhere." Any answer structured like "concludes that [thing thing] is [that thing]", we would want the former to match the Evidence and the latter to match the Conclusion. This answer is saying the author concludes that "something that was true at one time will therefore be true at all times. That doesn't reflect any move the author made here. This answer would be describing an argument that sounded more like, "Self-interest was the chief influence on human action during WWII. Thus, self-interest must always be the chief influence on human action."

    4% picked this

  4. concludes that, because an influence

    Reversed Parts

    Any time an answer is structured concludes that, because of X, Y we would want X to match the Evidence and Y to match the Conclusion. Was the Evidence saying an influence is the paramount (chief) influence on a class of events? No, the conclusion said that. We could eliminate this answer at this point. For what it's worth, the other idea in this answer choice is that "self-interest is the only influence on human action", which was not an idea that appeared at all in the argument. We were told that self-interest is the only influence that is involved in 100% of human actions, but not that it is the only influence on human action.

    22% picked this

  5. undermines its own premise that

    Wrong Flaw

    The wording "undermines its own premise" describes the famous Internal Contradiction flaw (which is almost never a correct answer). The author's conclusion does not undermine the premise in any way.

    4% picked this

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