Logical Reasoning

PT146 · S2 · Q16 The caffeine in coffee

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The caffeine in coffee stimulates the production of irritating acid in the stomach.

Conclusion

If you drink caffeinated coffee, darker roasts will irritate your stomach less than lighter roasts.

Evidence

Caffeine stimulates the irritating acid in the stomach. But darker roasts have more NMP than lighter roasts, and NMP tends to suppress acid production.

Evaluate

Given that darker roasts have more NMP, and NMP suppresses the irritating acid in your stomach, how could we still argue that lighter roasts are easier on your stomach?

There would to have to be something else different between darker and lighter that tips the scales back in favor of lighter roasts.

This argument is kind of like a Part vs. Whole argument. Since one part of darker roasts (the higher NMP) is better on your stomach, the author assumes/concludes that darker roasts overall are better on your stomach.

Goal

Look for an answer that addresses a potential difference between darker and lighter roasts, so that we might be able to argue that lighter roasts are actually easier on your stomach.

16.

The answer to which one of the following questions most helps in evaluating the argument?

Correct
Does extending the roasting time
Why this is right
This points to a potential difference between darker and lighter. Since we were told already that darker is roasted longer, if roasting time increases the amount of caffeine, then darker might have more caffeine. We were told that caffeine is what stimulates the irritating acids. So even if darker has more NMP (which suppress the acids), it might also have more caffeine, creating more acid in the first place. This gives us our potential weakener. We can argue that even if darker roasts have more acid-quelling NMP, lighter roasts are actually easier on the stomach because they have less acid-producing caffeine to begin with. (p.s. as a coffee lover, I happen to know that lighter roasts are more caffeinated, so if anyone else had that outside knowledge, this objection can feel counterintuitive, since we know the actual answer is No. But since a Yes answer would weaken, it's an important question to be resolved)
Skill tested: Evaluate · how this choice captures the argument's function is the move to repeat next time.
54% picked this
Does a reduction in acid
Unclear Impact
If the answer to this question is YES, then darker roasts, which have more NMP, which suppresses acid production, might have some adverse effect on stomach function. Could that be our way to argue that lighter roasts will irritate the stomach less? Not quite. An adverse effect on stomach function is too broad to be reliably about stomach irritation. It might mean that when acids are reduced, the speed of digestion and metabolism is slowed down. But all we care about is the truth value of the conclusion, which is exclusively about stomach irritiation. If the conclusion were, "thus, darker roasts are better for your stomach", then the discussion would be broad enough that adverse stomach function would be relevant. But since we only care about irritation, it's not clear whether this question would be addressing that.
25% picked this
Would coffee drinkers who drink
Out of Scope
We're comparing caffeinated dark roasts to caffeinated light roasts. This answer wants to compare the quantity of higher-caffeinated coffee consumed to the quantity of lower-caffeinated coffee consumed. We have no idea if or how darker and lighter roasts differ in terms of caffeine, so a question about more caffeine vs. less caffeine isn't clearly going to tell us anything about the potential difference between caffeinated dark and caffeinated light.
2% picked this
Do some coffee drinkers who
Too Weak / Irrelevant
First of all, the lead-in "if you drink caffeinated coffee, darker > lighter" implicitly means for a given quantity of coffee, darker > lighter. It's not saying "dark coffee drinkers have less stomach irritation than light coffee drinkers", where we might find it relevant how much each type of coffee drinker is consuming. So whether someone switching from lighter to darker would increase their coffee consumption is not our concern. We're only attempting to judge "when it comes to caffeinated coffee, which would irritate your stomach more: x mL of darker roast or x mL of lighter roast?" Finally, even if we were trying to use the YES answer as an objection, it's only got the strength of "some". If the answer is YES, then at least one person who switched from lighter to darker increased their coffee consumption by at least 1%. Big whoop.
12% picked this
Do lighter roasts of coffee
Out of Scope: health benefits
The conclusion wasn't a global evaluation of "which is better for you: darker or lighter?" It is narrowly about "which causes more stomach irritation: darker or lighter?" Even if we knew that lighter roasts had important health benefits that darker roasts lack, that wouldn't help us to argue that lighter roasts actually cause less irritation (we'd have to also know that these important health benefits include reducing acid irritation in your stomach).
6% picked this

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