LSAT Prep Notes: Conditional/Formal Logic, Necessary/Sufficient, and Reading Comprehension (Session Summary)

Session Overview

• Context: Tutor-led planning and drill for LSAT-style logical reasoning and reading comp. Technical issues prevented a perfect start; plan to check in later or reschedule if needed.
• Target timeline: September test date discussed; plan accelerates as we approach test time. Consider accommodations for extra time if needed (discussed in detail below).
• Core focus areas this session: four big topics in logic (conditional logic, formal logic, causal relationships, and required assumptions), plus practice with reading comprehension passages (Homing Pigeons and a comparative Indigenous media passage).
• Key recurring ideas: how to identify conclusion vs premises, the role of indicator words, the importance of not attacking premises, and proper use of term issues and takes-for-granted.

Four Big Topics (order to study them over several sessions)

• Conditional logic
• Formal logic
• Causal relationships
• Required assumption (necessary/sufficient conditions and their interaction)

Practical pacing, notes, and accommodations

• Time management tips: writing notes on passages, scoring, and speeding up with practice; plan to cut down note-taking once strategies are solid.
• Time accommodations discussion: extra time often available (e.g., 50% extra time for ADHD/learning diagnoses; some cases may allow double time). Doctor-form submission can trigger accommodations even without a diagnosis if anxiety or other test-related issues are shown.
• Note-taking guidance: for passages, write main idea in full sentence, plus a couple of key applications; avoid over-note-taking on side notes that won’t be used on questions.
• Strategy for check-ins: propose quick phone check-ins to discuss what to work on, to avoid exhausting tutoring time.

Conditional Logic: Training Wheels, Contraposition, and Skill-building

• What it is: When an argument uses conditional statements, identify the structure and diagram the dependency (training wheels help, not replace your reasoning).
• Two training-wheel rules (extracted from the session’s teaching):
  • If there is a requirement, place it on the right side of the conditional diagram.
  • If-then pattern: if this happens, then that always happens (a standard conditional pattern).
• Formal logic umbrella: conditional logic is a subset; LSAT explanations may distinguish it slightly from broader formal logic in some contexts.
• Contrapositive (the “training wheel” version):
  • For a conditional statement in the form $P <br /> ightarrow Q$, the contrapositive is $<br /> eg Q <br /> ightarrow <br /> eg P$.
  • Practical application: reverse the terms and negate them to derive the contrapositive.
• Concrete example: Driver’s license scenario
  • Original conditional: In order to obtain a driver’s license, one must prove residency in the state.
  • Diagram: Residency (required) → Driver’s license (outcome).
  • Contrapositive: If you do not have a driver’s license, then you do not prove residency (i.e., not (DL) → not (Residency)).
  • Important nuance: The converse (If you have residency, you automatically get a license) is not a valid contrapositive; that would be an illegal reversal if misused.
• Another example: Desk materials and construction
  • Premise: Only materials needed to build a desk are wood, saw, nails, and hammer.
  • Conclusion: I should be able to build a desk (since I have those materials).
  • Common pitfall: “Only those materials” is a heavy claim; fails to consider other required items (screws, hinges, drawers, tools, knowledge). This demonstrates taking a condition as sufficient or necessary when it isn't.
• Important terminology and relationships to recognize:
  • Necessary condition: A must be present for the result to occur.
  • Sufficient condition: A guarantees the result, but may not be required.
  • Proper contrapositive and negation are essential tools to test the logical relationships.
  • Inclusive vs exclusive OR: Or is usually inclusive unless stated exclusive (A ∨ B means either or both; exclusive would be A ⊕ B).
• Key examples from the session:
  • Driver’s license with residency and a test (the test is also required): discuss contrapositive involving residency and DL, and consider the proper negation for each component.
  • The “unplug the mouse” problem: should be analyzed as a necessary vs sufficient structure; the correct answer hinges on recognizing a conditional and the proper negation (i.e., if you unplug the mouse, the software becomes unusable; but that does not imply that unplugging is the only way to make it unusable).
  • A two-statement example: "If you unplug the mouse, software becomes unusable" versus the broader claim about whether software is unusable without the mouse; the correct answer often hinges on identifying the correct conditional form and whether the argument confuses sufficient with necessary.
• Quick drill approach (practice two problems per session): identify the conclusion, premises, and which statement is a take-for-granted vs a failure to consider, or a term issue.

Necessary vs Sufficient Conditions: Definitions, Examples, and Pitfalls

• Definitions:
  • Necessary condition: A condition N is necessary for R if R implies N; if N is not met, R cannot occur. In symbols: $R <br /> ightarrow N.$ Contraposition: $<br /> eg N <br /> ightarrow <br /> eg R.$
  • Sufficient condition: A condition S is sufficient for R if S implies R; S guarantees R, but R might occur via another path as well. In symbols: $S <br /> ightarrow R.$ Contrapositive: $<br /> eg R <br /> ightarrow <br /> eg S.$
• Left-right notation convention (training-wheel reminder): In a conditional, place the condition (requirement) on the right and the resulting condition on the left for easy diagramming; remember the directionality matters.
• Examples from the session:
  • Driver’s license example:
  • Rule: Residency is a necessary condition to obtain a DL: Residency → DL.
  • Test condition: You also need to pass a driving test (another requirement). If you fail the test, you do not get the license.
  • Proper contrapositive handling avoids the mistake of claiming that residency alone guarantees a license.
  • Desk-building example:
  • Stated: Only materials needed are wood, saw, nails, hammer (premise).
  • Flaw: It ignores other required items and knowledge (screws, drawers, assembly know-how). This misclassifies a condition as both necessary and sufficient.
• Common mistakes to watch for:
  • Illegal reversal: reversing a conditional incorrectly (e.g., assuming DL → Residency is enough to guarantee the license).
  • Confusing necessary with sufficient: claiming a sufficient condition is necessary (or vice versa).
  • Neglecting other necessary conditions or prerequisites (e.g., testing, documents, or tools beyond the stated ones).
  • Treating OR as exclusive without explicit instruction; default to inclusive OR unless stated otherwise.
• How to approach problems:
  • Step 1: Identify the conditional(s) in the stimulus.
  • Step 2: Put any stated requirements on the right and outcomes on the left.
  • Step 3: Check for contrapositive forms and proper negation using the rules above.
  • Step 4: Distinguish which condition is necessary, which is sufficient, and which is neither.
  • Step 5: Watch for “takes for granted” vs “fails to consider” vs “term issue” language and classify the flaw accordingly.
• Drill prompts discussed in-session:
  • Example 1 (pool/gym): Determine whether the flaw is a take-for-granted, fails to consider, or term issue, and identify the correct answer choice (the typical correct move is to call out an illegal reversal and then classify the condition as necessary vs sufficient).
  • Example 2 (driver’s license with residency and test): Recognize the correct classification of necessary vs sufficient; identify if there are additional requirements beyond the stated ones.
  • Example 3 (desk building, two-branch issues): Practice contrapositive handling and the recognition of multiple conditions that together guarantee the result.
• Practical takeaway: You should be able to diagram a conditional argument and show your work, then confirm the correct answer by applying the definitions (necessary/sufficient) and the proper contrapositive logic.

Conditional Logic Drill Set (Practice Plan)

• Next steps: The student will work on a conditional logic drill set as part of the assignment; the tutor will review the differences and ensure understanding of sub-types (e.g., chain conditionals, necessary vs sufficient). Expect more complex prompts that mix “takes for granted,” “fails to consider,” and term-issue formulations.
• Drill expectations:
  • Write out the conditional logic explicitly for each prompt.
  • Identify the conclusion and the premises.
  • Determine whether the flaw is an illegal reversal, a failure to consider, or a term issue.
  • Distinguish between necessary and sufficient conditions and apply the contrapositive correctly.

Reading Comprehension (Two Passages): Indigenous Videography and Method of Reasoning

• PT context: The session includes discussion of a long reading passage about Indigenous use of videography and Western ontology, with multiple positions.
• Authors and positions in the passage (as discussed):
  • James Weiner: Argues that indigenous groups adapt to Western values via video technology; claims such media can be the “final boss of colonialism” and can harm native ontologies.
  • Faye Ginsburg: Counterpoint; argues indigenous groups use videography as an outlet but do not necessarily adopt Western ontology; broader view of use and adaptation.
  • Terrence Turner: Provides a counterexample/alternative perspective that shows video representations can conform to the ceremonies’ own principles of beauty, suggesting less wholesale Westernization.
• Key concepts introduced:
  • Ontology: The worldview or the structure of reality through which a culture interprets the world.
  • Method of reasoning: How an author constructs an argument, independent of the content. Important for “reading for method” questions.
  • The role of evidence and example: An example may be used to support a claim; the passage may require you to analyze why that example was used and what it demonstrates about the argument.
• Main idea (as discussed in the session): There is debate about whether video technology changes Indigenous cultures to align with Western ideologies or whether it can coexist with Indigenous values; the author presents multiple viewpoints and aims to present a balanced view rather than a one-sided argument.
• Traits of the examples and discussion:
  • The Timber Turner/Weiner discussion uses examples (like camera work and ceremony) to illustrate how representation may or may not align with traditions.
  • The author notes that the passage uses both descriptive and evaluative elements, requiring attention to the author’s stance and tone across sections.
• How to answer related questions:
  • Main idea questions: identify the author’s overall stance and whether it’s balanced or leaning toward one side.
  • Analogy/Example questions: determine why a particular example is used and what it reveals about the author’s argument.
  • Tone and purpose questions: assess whether the tone is neutral, approving, or critical of one side.
  • The reading includes a section on “method of reasoning,” which is about how the author constructs an argument rather than what the argument claims.
• Preparing for the section:
  • Be ready to summarize the debate (Weiner vs. Ginsburg vs. Turner) accurately and concisely.
  • Practice identifying the author’s stance and how the examples support that stance.
  • Practice choosing the answer that best captures the full scope of the passage (not just one side) when asked for the best overall summary.

Tone, Nuance, and Strategy for Reading Comprehension Passages

• The professor emphasizes avoiding overcommitment to one side when the passage presents multiple viewpoints.
• When asked to summarize or capture the main idea, there are often more nuanced options than a single-sentence takeaway; aim for a balanced articulation that reflects the range of positions.
• In questions about the author’s method of reasoning, focus on how the argument is structured, rather than the specific content of the claims.
• When dealing with a complex comparative passage, pay attention to how the author uses evidence and how it supports or challenges the key positions.

Assignments, Schedule, and Follow-ups

• Upcoming tasks:
  • Complete the Conditional Logic Drill Set (as requested by the tutor).
  • Review the last Power Test (PT) assignments you’ve worked on, and be prepared to discuss them.
  • Read PT 75 Section 2 (Reading Comprehension) and practice the first passage (Homing Pigeons analogy) with the approach described (primary vs secondary, purpose, main idea, and application).
• Check-in planning: The tutor proposed a quick phone check-in to discuss what to work on next, to avoid consuming tutoring hours unnecessarily.
• Scheduling: A check-in can be arranged for next week or the following week to set the trajectory and ensure preparedness for the upcoming test.

Quick Reference: Key Symbols and Concepts (LaTeX-formatted)

• Conditional logic:
  • If P then Q: $P <br /> ightarrow Q$
  • Contrapositive: $<br /> eg Q <br /> ightarrow <br /> eg P$
• Necessary vs Sufficient:
  • Necessary condition N for R: $R <br /> ightarrow N$
  • Sufficient condition S for R: $S <br /> ightarrow R$
  • Contrapositives:
  • From $R <br /> ightarrow N$, contrapositive is $<br /> eg N <br /> ightarrow <br /> eg R$
• OR logic:
  • Inclusive OR: A \/ B (A or B or both)
  • Exclusive OR would be a different construct (often denoted by ⊕ or explicitly stated as exclusive)
• Examples and diagramming: use training wheels to place the condition on the right and outcomes on the left; diagram chain conditionals to see dependencies clearly.

Notes for Study Sessions

• Practice pacing by timing yourself on drills and progressively reduce note-taking while preserving the essential elements: conclusion, premises, and the key conditional relationships.
• Build fluency with contrapositive, negation, and the differences between necessary vs sufficient conditions. Use the illustrated driver’s license and desk-building examples to reinforce this.
• When engaging with reading comprehension passages, practice identifying the main point, the author’s stance, and the purpose of each example, especially in comparative or method-of-reasoning questions.
• Keep track of the difference between takes-for-granted and fails-to-consider; term-issue questions require careful attention to how terms are used across premises and conclusions.
• Prepare for the next session by completing the conditional logic drill set and reviewing the latest PTs you've worked on, and be ready to discuss any unclear items during the next check-in.