Logical reasoning PrepTest 154 · Section 4 · Question 7

Incorrect. This isn't necessarily true, but it isn't a fallacy of causation. The problem here is more of an issue of modality; it's possible that in some circumstances more of a treatment might be more curative, but "will be more effective" is way too strong (and would kill people, in this situation).

Incorrect. Kind of similar to the stimulus, but it's flipped on its head, making it significantly less fallacious. It's still a weak argument, but there's no causal fallacy in saying that a deficiency of something can probably be treated by applying that thing.

Incorrect. This is a somewhat tempting trap, because there is an element of causation here; since lack of food causes health issues, maybe the more food you eat the more healthy you'll be. But this is actually more of an issue with a missing necessary condition. Simply eating more CAN make people healthier, if they have malnutrition. The conclusion forgets about the necessary condition of "malnutrition" and just says eating more makes people healthier.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
The stimulus describes a plant disease called "late blight," and tells us it can be cured by applying a copper solution to the leaves. So, it concludes, late blight is caused by copper deficiency.

Answer Anticipation:
Giant, obvious fallacy of causation here. Just because a treatment cures a disease doesn't mean that a lack of that treatment caused the disease. Otherwise we'd all be diagnosed with "antibiotic deficiency" every time we got strep throat. So, expect a correct answer choice to display a fallacy of causation in the same form, e.g., "if this fixes the problem, then lack of this must have caused the problem."

Answer Explanation:
Exactly what we anticipated: if something is effective as a treatment for a particular problem, then a deficiency of that thing must have caused the problem. So all sunburns are caused by aloe vera deficiencies, and tiredness is caused by a caffeine deficiency (actually, in law school you'll discover that last bit is true).

Key Takeaway:
Preparation is key in all parallel flaw questions. If you go to the answer choices before you can clearly describe the fallacy in the stimulus, you may choose a trap answer. Stay on the stimulus until you are sure you know what's wrong with it. Maybe even try making up a couple parallels yourself, if you have the time.

Incorrect. This is an issue of conditionality, not causality. If calcium deficiency ==> brown spots, the argument claims, NOT calcium deficiency ==> NOT brown spots. Fallacy of the inverse.