Logical Reasoning

PT4 · S4 · Q13 Physician: The patient is suffering

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Physician: The patient is suffering either from disease X or else from disease Y, but there is no available test for distinguishing X from Y. Therefore, since there is an effective treatment for Y but no treatment for X, we must act on the assumption that the patient has a case of Y.

Premise

The patient has either disease X or disease Y, but there is no test to distinguish them. There is an effective treatment for Y but no treatment for X.

Conclusion

We must act on the assumption that the patient has Y.

Evaluate

The reasoning: success (curing the patient) is only possible if it is Y (since X has no treatment). So we proceed as if Y is the case — because that is the only path on which our action can succeed. The principle: when success requires a favorable circumstance, assume the favorable circumstance.

Goal

Find the principle: when success is only possible under a favorable (uncontrollable) circumstance, base the strategy on the assumption that the circumstance is favorable.

13.

The physician’s reasoning could be based on which one of the following principles?

In treating a patient who
Bad Description
This says treating the disease matters more than diagnosing it. The physician's reasoning is not about ranking treatment over diagnosis — diagnosis is impossible here, not deprioritized. The physician is choosing among treatment strategies based on which scenario allows for success, not arguing that diagnosis is unimportant.
12% picked this
If circumstances beyond a decision
Opposite
This is the reverse of the physician's logic. The physician assumes the favorable circumstance (it is Y, which is treatable). This principle says assume the unfavorable. If the physician followed this, they would assume it is X (untreatable) and not even attempt treatment — the opposite move.
1% picked this
When the soundness of a
Bad Description
This says test the assumption first. But the physician's situation is precisely that no test is available — testing is impossible. So this principle does not match. The physician must act without testing, which is the opposite of what this principle prescribes.
11% picked this
Correct
When success is possible only
Why this is right
This nails the physician's reasoning. Success (curing the patient) is only possible if it is Y — that is, only if the uncontrollable circumstance (which disease the patient has) is favorable. The physician's strategy is then based on the assumption that this circumstance is favorable: treat as if it is Y. Apply the principle, and the physician's reasoning falls out as a direct application.
Skill tested: Principle-Conform · how this choice captures the argument's function is the move to repeat next time.
55% picked this
When only one strategy carries
Bad Description
This says change circumstances to fit the strategy. The physician cannot change which disease the patient has — the circumstance is fixed and unknowable. The principle the physician is following is to act as if the circumstance is favorable, not to alter the circumstance.
21% picked this

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