PrepTest 154

[lcid:3712] Prep Test 154 LSAT — Logical Reasoning — S1 Logical reasoning

Question prompt

Philosopher: A person is Remaining source text redacted.

Answer choices

  1. A
    An alternative action is Remaining source text redacted.
    Why choice A is not credited
    Incorrect. not Morally responsible → not Alternative genuinely available

    This answer is an illegal reversal of the contrapositive. (If you had diagrammed the contrapositive of this answer—Alternative genuinely available → Morally responsible—it still would have been a reversal, just of the original statement.)
  2. B
    People are not morally Remaining source text redacted.
    Why choice B is not credited
    Incorrect. There's no premise established that provides information about the frequency that actions fall into any of these categories, so this answer stating that most actions don't create moral responsibility is unsupportable.
  3. C
    A person is morally Remaining source text redacted.
    Why choice C is not credited
    Incorrect. Alternative genuinely available → Morally responsible
    This answer is an illegal reversal of the chain.
  4. D
    If it would be Remaining source text redacted.
    Why choice D is not credited
    Incorrect. Morally wrong → Genuinely available

    An action being morally wrong only shows up in the stimulus when discussing alternatives. There, it's stated that a morally wrong alternative action isn't genuinely available to someone, so this answer, if anything, cannot be true.
  5. E
    An action is not Remaining source text redacted.
    Why choice E matches the stem
    Correct. Argument or Facts:
    Facts

    Question Type:
    Must Be True

    Stimulus Summary:
    Morally responsible → Action performed freely
    Action performed freely → Alternative genuinely available
    Alternative genuinely available → not Alternative morally wrong

    Answer Anticipation:
    While the statements in this stimulus might make it feel like a Principle question, the stem doesn't refer to it as such, and the conditionals chain together, so we shouldn't think of it as a Principle question. Instead, we should treat it as a normal Must be True question with conditional premises.

    And the conditionals all chain together nicely, without needing to take contrapositive:
    Morally responsible → Performed freely → Alternative genuinely available → not Alternative morally wrong
    Alternative morally wrong → not Alternative genuinely available → not Performed freely → not Morally responsible

    With the chain and its contrapositive built, it's time to head to the answers.

    Answer Explanation:
    Alternative morally wrong → not Performed freely
    If you use the "unless = if not" trick to diagram this, be careful on the double negative here ("if not not morally wrong" is the same as "if morally wrong," as we diagrammed here). This answer reflects the contrapositive of our chain, so it's the correct answer. (If you had diagrammed the answers as "Performed freely → not Alternative morally wrong," then you'd see that this answer is supported by the chain.)

    Key Takeaway:
    Conditionals in Must Be True questions allow you to apply a process that proves the correct answer. Getting good at conditionals will help not only with Logical Reasoning (about 1/6 questions), but also with Logic Games (over half of which have a conditional rule).

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