Electricity would revolutionize agriculture according to a prediction of the…
2025
Electricity would revolutionize agriculture according to a prediction of the not-so-distant future published in 1940. Electrodes would be inserted into the soil, and the current between them would kill bugs and weeds and make crop plants stronger.
Which of the following, if true, most strongly indicates that the logic of the prediction above is flawed?
- A.
In order for farmers to avoid electric shock while working in the fields, the current could be turned off at such times without diminishing the intended effects
- B.
If the proposed plan for using electricity were put into practice, farmers would save on chemicals now being added to the soil.
- C.
It cannot be taken for granted that the use of electricity is always beneficial.
- D.
Since weeds are plants, electricity would affect weeds in the same way as it would affect crop plants.
Show answer & explanation
Correct answer: D
Concept: A prediction is logically flawed when it assumes two things will react differently to the exact same cause, without giving any reason why the two things actually differ in the way that matters. To expose such a flaw, find a fact showing the two things are actually alike in the relevant respect - that fact undercuts the unjustified assumption the prediction depends on.
Application: The 1940 prediction claims a single electrical current running through the soil would kill weeds while simultaneously strengthening crop plants - two opposite effects from one shared cause. Since weeds and crop plants are both, at the biological level, plants, the prediction never explains why the same current would harm one and help the other. Pointing out that weeds and crop plants are both plants directly exposes this unsupported assumption, making it the strongest indication that the prediction's logic is flawed.
The option about switching the current off for farmer safety addresses an operational precaution, not whether the prediction's claim of differing effects is logically justified.
The option about saving on chemicals restates a benefit consistent with the prediction succeeding, so it supports rather than undermines the argument.
The general caution that electricity is not always beneficial is too broad - it never engages with the specific unsupported assumption that the same current affects weeds and crops differently.
Result: Because nothing in the prediction explains why an identical current would kill one kind of plant while strengthening another, the statement that weeds and crop plants - both being plants - would be affected the same way is what most strongly reveals the flaw.