Logical ReasoningDifficulty: Hard

PT158 S2 Q13 Explanation

The widespread use of encryption

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsMain Conclusion

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Stimulus

The widespread use of encryption software, which makes electronic documents accessible by password only, will bring the writing of biographical history virtually to an end. Public figures' private correspondence and diaries are intended to be confidential when written, but they later become biographers' principal sources. In the future, most such documents are material will be unavailable to historians unless they have the necessary passwords.

What this question is testing

Main Conclusion

Conclusion

Encryption is going to kill biographical history. Done. Game over for biographers.

Evidence

Biographers depend on private letters and diaries that eventually become public. But in the future, all those juicy documents will be locked behind passwords that historians will never have. No documents, no biographies.

Evaluate

The argument is a domino chain: encryption locks documents, locked documents are inaccessible, inaccessible documents mean no biographies. The first sentence announces the grand conclusion; the rest explains the mechanism. Do not confuse the steps in the chain with the final destination.

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The question
13.

Which one of the following most accurately expresses the main conclusion drawn

Answer choices

  1. Premise8% picked this

    In the future, most private correspondence and diaries of public figures will be stored

    This answer restates a premise of the argument, not the main conclusion. The statement that most private correspondence and diaries will be stored as encrypted text is presented as a factual prediction about future technology adoption. It is one link in the causal chain that supports the main conclusion. The main conclusion is about the consequence of this encryption — the end of biographical history. This answer describes the cause (encrypted storage), not the effect (the end of biographical writing). In the argument's structure, this fact is offered as evidence for why biographical history will suffer, not as the main point the argument is trying to establish.

  2. Correct67% picked this

    The widespread use of encryption software will cause the writing of biographical history to decline

    Why this is right

    This answer accurately expresses the argument's main conclusion. The first sentence of the stimulus declares that the widespread use of encryption software will bring biographical history "virtually to an end." This is the broadest, most consequential claim in the argument — everything else supports it. The evidence about private documents being biographers' sources, the prediction about encrypted storage, and the intermediate conclusion about historians lacking passwords all feed into this overarching claim. This answer paraphrases the first sentence faithfully: encryption will cause biographical history to virtually cease. It captures the right claim at the right level of generality without overstating or understating the argument's position.

    Skill tested: Main Conclusion · how this choice captures the argument's function is the move to repeat next time.

  3. Assumption / Inference10% picked this

    Historians will probably not have access to much of the private correspondence and diaries of public

    This answer says historians will probably not have access to much private correspondence and diaries of public figures in the future. While this is a reasonable inference from the argument, it functions as an intermediate conclusion or unstated implication — not the main conclusion. The argument's main conclusion is about the broader consequence of this inaccessibility: the end of biographical history. This answer describes a step in the causal chain (historians lose access) rather than the final result (biographical history ends). The main conclusion is the ultimate destination of the reasoning; this answer stops one step short.

  4. Intermediate Conclusion, Last-Claim Trap14% picked this

    In the future, biographers' access to the most interesting, revealing material will be determined by their knowledge

    This answer says biographers' access to interesting material will be determined by the availability of passwords. While this is implied by the argument, it is an intermediate conclusion, not the main conclusion. The argument uses this point — that password access will control information availability — to support its broader claim that biographical history will virtually end. This answer describes a mechanism or condition, not the ultimate consequence. Additionally, this is a classic "last-claim trap": test-takers sometimes select the last statement in an argument as the main conclusion simply because it appears at the end. But in this argument, the main conclusion appears in the first sentence, and the final sentence provides supporting detail.

  5. Assumption / Inference1% picked this

    Public figures' private correspondence and diaries are the most interesting and revealing sources for the

    This answer says public figures' private correspondence and diaries are the most interesting and revealing sources for biographical history. The argument does say that this material constitutes biographers' "principal sources" and refers to it as "the most interesting, revealing material." However, this is a background premise or assumption of the argument, not its main conclusion. The argument uses this claim to explain why the loss of access to encrypted documents would be devastating to biographical history. It is a building block, not the final structure. The main conclusion is about the consequence of losing access to these sources: the end of biographical history writing.

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