QUESTION TYPE: Sufficient Assumption
CONCLUSION: Well being unchanged ➞ right
- Well being up ➞ right
right ➞ well being up
- Well being down ➞ wrong
wrong ➞ well being down
- wrong ➞ well being down
well being down ➞ wrong
ANALYSIS: The two premises seem similar, but they’re not. One uses “if”, and one uses “if and only if”. Those are very different statements!
The “if and only if” statement is a dual statement. It’s items 2 and 3 in the reasoning above. You have to draw both versions to capture the full reasoning.
(Note: on my own test, I just draw single letters. I’m using full words here for clarity in the explanation. But my own drawings are faster to draw, because they’re short.)
We have to prove that something unchanged is morally right. How do we do that? On sufficient assumption questions, you should take the conclusion, then split it into halves:
We’re going to fill in the evidence next. This isn’t obvious. The evidence doesn’t mention “unchanged”. How do we connect it? Well, we have this statement: “well being down ➞ wrong”.
What is @well being not [email protected]? It’s any situation where well being is up, or unchanged. So, if well being is unchanged, we can conclude @not [email protected] So we can add this onto our separated conclusion:
unchanged ➞ wrongright
The gap should be obvious now. If we say “wrong ➞ right”, then the conclusion is true.
- The stimulus already told us that “wrong” is a necessary condition for actions which reduce aggregate well being.
On sufficient assumption questions, you’re looking for new information which adds to the argument and proves the conclusion true. This answer isn’t new info, so it can’t be right.
- If this had said “an action must be either right or wrong”, it would have been right.
This answer instead says “if something is wrong, it’s not right”. That’s no good. We’re looking for something that says “if something is not wrong, it is right”.
- CORRECT. In the reasoning, we saw well being down ➞ wrong. Something which leaves things unchanged isn’t down, and therefore isn’t wrong. This answer says that because that action isn’t wrong, it is therefore right.
- This tells us that actions which leave well being unchanged exist. That doesn’t matter. The stimulus was about what happens if they exist.
(E.g. if I say “you’ll be wealthy if you win the lottery”, my statement is true whether or not you actually win the lottery.)
- This introduces a new term not mentioned in the argument. That can’t help connect anything. (“Consequences” is much broader than affecting the well being of people.)
Free Logical Reasoning lesson
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