Logical Reasoning

PT136 · S2 · Q12 Because dried peat moss

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Because dried peat moss, which is derived from sphagnum moss, contains no chemical additives and is a renewable resource, many gardeners use large amounts of it as a soil conditioner in the belief that the practice is environmentally sound.

Conclusion

(They are mistaken) Using sphagnum moss as a soil conditioner is not environmentally sound.

Evidence

Sphagnum moss is maybe the biggest single contributor of oxygen to the atmosphere, and the garden soil industry is depleting is.

Evaluate

We know we want the conclusion to let us prove that using SM as a soil conditioner isn't an environmentally sound practice, so that's the right side of our principle:

practice → environmentally is not sound

What should go on the right side? Why is this practice environmentally unsound?

Because it depletes one of the biggest oxygen providers in the world.

Goal

So we want something like

depletes one of practice is not the biggest sources → environmentally sound of oxygen globally

12.

Which one of the following principles, if valid, most helps to justify the argument's reasoning?

  1. Using a product may be

    Too Weak: may be unsound

    The conclusion may be true is almost always going to be too weak for any Strengthen / Sufficient Assumption / Justify task. SM is a renewable resource and contains no chemical additive, so this rule does apply, but it just allows for the possibility that using SM may be unsound.

    29% picked this

  2. Correct

    A practice is not environmentally

    Why this is right

    This is pretty similar to our prephrase. The use of SM significantly reduces oxygen supply, since we are told that SM is basically the #1 oxygen supplier there is, and the garden soil industry is rapidly depleting the supply of SM.

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

    62% picked this

  3. A practice is environmentally sound

    Bad Conclusion / Premise Match

    Since this rule says, _____ ? environmentally sound we can instantly get rid of it. We need a rule that has "not environmentally sound" on the right side. Beyond that deal breaker, the trigger of this rule doesn't apply to sphagnum moss; we aren't told that it helps to protect rain forests. Its oxygen output is just compared to that of rain forests.

    2% picked this

  4. If the environmental benefits of

    Bad Conclusion / Premise Match

    This answer can also be summarily rejected because it's set up to conclude that something is environmentally sound, and we need a rule that allows us to conclude that something is not environmentally sound. We also wouldn't haven't been able to precisely judge whether the benefits outweighs the costs when it comes to the environmental impact of using sphagnum moss (we were told good and bad things, but not how to weight those against each other).

    5% picked this

  5. If the practices of an

    Weak Conclusion / Premise Match

    We're trying to prove that a practice is environmentally unsound, not that it should be banned. It's okay for our answer to be stronger than what we need, but it's not clear that saying "something should be banned" necessarily means that it was "environmentally unsound". It's also less clear from the paragraph that using sphagnum moss threatens a vital resource. It reduces the supply of oxygen, but does it threaten oxygen? Because the trigger of this rule is harder to match up and because the conclusion isn't a solid meaning match for "not environmentally sound", this loses out to the correct answer.

    2% picked this

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