Logical Reasoning

PT138 · S4 · Q17 Humankind would not have survived

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Humankind would not have survived, as it clearly has, if our ancestors had not been motivated by the desire to sacrifice themselves when doing so would ensure the survival of their children or other close relatives.

Evidence

Humankind survived. Survived Survival required Survived → Sac sacrifice. Sacrifice is Sacrifice → Altruism Altruism.

Conclusion

Ancestors were altruistic. Altruism

Evaluation

This is a tough argument to see in conditional logic, but because of the repeating symbols (sacrifice shows up twice, so does altruism) and because of the "if" in the first sentence, we probably should try to see the math in the argument. It ends up being a straightforward type of argument, with two conditional premises that chain together, a fact that triggers the chain, and a conclusion that states the outcome of the chain.

Goal

We need something resembling this. A → B B → C A. ⎯⎯⎯⎯⎯⎯⎯⎯ C.

17.

Which one of the following arguments is most similar in its reasoning to the argument above?

  1. Correct

    Students do not raise their

    Why this is right

    Raise grades → More study time More study time → Good time Raise grades. management ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Good time management

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

    65% picked this

  2. Organisms are capable of manufacturing

    Bad Premise Match Bad Conclusion Match

    We only have 2 premises (original had 3), so that's a quick way to get rid of this. We don't have two conditional premises; we have one conditional and one MOST claim. The conclusion also brings in a brand new idea (bug-eating insects). carbs from others → make own most plants → carbs from bugs ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Bug-eating plants → Photosynthesis

    10% picked this

  3. If fragile ecosystems are not

    Bad Premise Match Bad Conclusion Match

    We only have 1 premise (original had 3), so that's a quick way to get rid of this. We don't have two conditional premises; we have one conditional. The conclusion is a conditional (the original was not). endemic species → only lives in one eco ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ government protected ecosystems → endemic species die

    5% picked this

  4. The natural resources used by

    Bad Premise Match

    We only have 2 premises (original had 3). We don't have two conditional premises; we have one conditional and one "probable" claim. natural resources depleted → replace natural resources with alterative replace natural resources with alternative → generally requires more power ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ more power → depleted

    15% picked this

  5. Public buildings do not harmonize

    Weak Premise Match

    We only have 2 premises (original had 3). We have two conditional premises that chain together, but we also need a factual premise that triggers a factual conclusion. This conclusion is either / or. Public buildings harmonize with surroundings → well designed well designed → expensive to construct ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Public buildings → expensive or harmonizing

    5% picked this

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