PHIL 109 - Fallacies Study Guide

One-Page Recognition Chart

  • Subjectivism: ME / I believe or want it
  • Appeal to Majority: Numbers make it true
  • Appeal to Force: Threats
  • Ad Hominem: Attack the person
  • Appeal to Authority: Bad / non-credible authority
  • False Dichotomy: Only two options
  • Post Hoc: A happened before B, so A caused B
  • Hasty Generalization: General claim from too little evidence
  • Accident: General rule applied without noting special features
  • Slippery Slope: Minor action →\rightarrow major bad consequences
  • Begging the Question: Conclusion is also a premise
  • Equivocation: One word used in two different ways
  • Appeal to Ignorance: Not known / not proven, therefore true or false
  • Missing the Point: Reasons support a different conclusion
  • Straw Man: Distort the opponent's argument
  • Red Herring: Distract from the issue
  • Non Sequitur: Conclusion does not follow at all

Fallacies of Relevance

Arguments in this category utilize premises or reasons that are not relevant enough to establish the logical truth of the conclusion.

  • Subjectivism

    • Status: Core Test Fallacy
    • Definition: Holding a proposition to be true merely because one believes or wants it to be true.
    • Key Hint: The reason given is ME ("I am the reason this is true/false").
    • Red Flag Indicators: Look for personal feelings, desires, denial, statements like "that is how I was raised," or "that is true for you but not for me."
    • Example: "I cannot even think about failing this class, so I must not be failing."
    • Logical Breakdown: A personal state of mind or internal wish does not determine whether a claim is objectively true in reality.

  • Appeal to Majority

    • Status: Core Test Fallacy
    • Definition: Using the fact that a majority of people believe a claim as the primary reason it must be true.
    • Key Hint: Numbers make it true.
    • Red Flag Indicators: Look for terms such as "everyone," "most people," "most students," "millions of people," or "everybody says."
    • Example: "Most students think the professor is wrong, so the professor must be wrong."
    • Logical Breakdown: An entire group or majority population can be mistaken just as easily as an individual.

  • Appeal to Force

    • Status: Core Test Fallacy
    • Definition: Using a physical, psychological, or situational threat as a reason to force belief in a proposition.
    • Key Hint: Threats.
    • Red Flag Indicators: Look for "believe this or else" scenarios or the explicit use of punishment to coerce agreement.
    • Example: "Believe my political claim, or I will make sure you lose your position."
    • Logical Breakdown: A threat can physically or emotionally pressure a person into compliance, but it provides zero objective evidence that the underlying claim is true. A distinction exists between a threat used to make someone believe a claim versus a threat used merely to force someone to perform an action.

  • Ad Hominem

    • Status: Core Test Fallacy
    • Definition: Rejecting a proposition by attacking the person asserting it rather than addressing the argument itself.
    • Key Hint: Attack the person ("You Suck").
    • Red Flag Indicators: Look for personal insults, accusations of hypocrisy, or claims regarding a person's underlying motives instead of analyzing their evidence.
    • Example: "Do not listen to her argument about attendance; she is lazy."
    • Logical Breakdown: A person's character flaws, habits, or traits do not make their factual proposition false.
    • Special Ad Hominem Subtypes:
    • Abusive: Directing irrelevant, rude, or offensive personal insults at the claimant.
    • Tu Quoque: Responding with "You are, too!"—pointing out the claimant's personal hypocrisy rather than refuting their argument.
    • Poisoning the Well: Preemptively attacking a person's integrity by claiming self-interest, bias, or ulterior motives to discard their claim before it is evaluated.

  • Appeal to Emotion

    • Status: Homework Only (Excluded from Main Test)
    • Definition: Manipulating an audience's emotional reactions to gain acceptance for a proposition.
    • Key Hint: Emotional manipulation.
    • Red Flag Indicators: Look for appeals to pity, fear, guilt, excitement, sadness, or sympathy substituted in place of rational evidence.
    • Example: "You have to agree with my claim because it would break my heart if you did not."
    • Logical Breakdown: An emotional reaction or feeling does not provide factual support for the truth of a claim.

Inductive Fallacies

  • Appeal to Authority (Appeal to BAD Authority)

    • Status: Core Test Fallacy
    • Definition: Relying on an authority figure who lacks true credibility or relevant expertise regarding the subject matter.
    • Conditions of Credibility: Genuine credibility requires proper education, position, and verifiable achievement within the specific domain in question.
    • Key Hint: Bad / non-credible authority.
    • Red Flag Indicators: Look for celebrities, social media influencers, professional athletes, or famous figures treated as experts outside their field.
    • Example: "A famous actor says this medical treatment works, so it must work."
    • Logical Breakdown: Citing a non-credible authority fails to provide adequate reasoning for a claim. While a bad authority can occasionally utter a factual truth by accident, relying on their statement as the ground for belief remains fallacious.

  • False Dichotomy

    • Status: Core Test Fallacy
    • Definition: Presenting an either/or premise that limits options to only two choices when additional relevant alternatives exist.
    • Key Hint: Either/Or — Two Options.
    • Red Flag Indicators: Look for "either A or B," "you are with us or against us," or extreme black-and-white framing that ignores middle ground.
    • Example: "Either you get an A in this class or you learned nothing."
    • Logical Breakdown: The argument unjustifiably excludes valid alternatives from consideration.

  • Post Hoc

    • Status: Core Test Fallacy
    • Definition: Inferring that event A caused event B strictly because event A occurred prior to event B.
    • Key Hint: Temporal sequence treated as cause ("Something happened already and something will happen").
    • Red Flag Indicators: Look for "after this, therefore because of this," reliance on lucky charms, superstitions, or time order used as sole proof of causality.
    • Example: "I wore my lucky socks before the exam and got an A, so the socks caused my A."
    • Logical Breakdown: Countless events occur prior to an outcome. Establishing actual causation requires demonstrating a direct physical or logical mechanism beyond simple chronological succession.

  • Hasty Generalization

    • Status: Core Test Fallacy
    • Definition: Affirming a broad general conclusion based on an insufficient amount of evidence.
    • Key Hint: Too little evidence; evaluate sample number and variety.
    • Red Flag Indicators: Look for broad claims derived from a single instance or weak sample lacking diversity.
    • Example: "I ate at that restaurant once and hated my meal, so all of their food is horrible."
    • Logical Breakdown: The sample size is too small or unrepresentative. Sample variety is the single most important factor in validating an inductive generalization.

  • Accident (Hasty Application)

    • Status: Core Test Fallacy
    • Definition: Applying a general rule to a specific case without accounting for exceptional or special features that make the rule inapplicable.
    • Key Hint: Hasty application — the structural opposite of Hasty Generalization.
    • Red Flag Indicators: Look for a widely accepted rule applied rigidly or mechanically to an extreme or unusual scenario.
    • Example: "You should always tell the truth, so you must tell a mugger who stole your phone exactly where you live."
    • Logical Breakdown: General rules derived from inductive reasoning carry natural exceptions and contextual limits.

  • Slippery Slope

    • Status: Core Test Fallacy
    • Definition: Asserting without evidence that an initial minor action will trigger an inevitable sequence of escalating events ending in disaster.
    • Key Hint: Minor action leads to major consequences.
    • Red Flag Indicators: Chains of cause-and-effect claims (A→B→C→DA \rightarrow B \rightarrow C \rightarrow D disaster) where a tiny first step guaranteed an extreme outcome.
    • Example: "If my son steals one piece of candy, he will stop caring about all rules, become a criminal, commit horrible crimes, and end up dead or in jail."
    • Logical Breakdown: Every link in a causal chain must be supported by evidence; assuming automatic continuous disaster is unwarranted.

  • Composition

    • Status: Homework Only
    • Definition: Inferring that a property shared by individual parts must automatically belong to the whole.
    • Key Hint: Part →\rightarrow Whole.
    • Red Flag Indicators: Premises describing individual parts yielding a conclusion about the entire collective entity.
    • Example: "Every player is talented, so the team as a whole must be unbeatable."
    • Logical Breakdown: A structured whole possesses organizational properties distinct from the isolated traits of its components.

  • Division

    • Status: Homework Only
    • Definition: Inferring that a property belonging to a whole group or structure must automatically apply to each individual part.
    • Key Hint: Whole →\rightarrow Part.
    • Red Flag Indicators: Premises describing an entire system, organization, or group yielding a conclusion about specific individual members.
    • Example: "The university is wealthy, so every student at the university must be wealthy."
    • Logical Breakdown: Attributes of an aggregate system do not necessarily transfer down to every constituent element.

Fallacies of Presumption and Diversion

  • Begging the Question (Circular Argument)

    • Status: Core Test Fallacy
    • Definition: Structuring an argument such that the conclusion appears as a premise, either verbatim, rephrased, or embedded within a circular loop.
    • Key Hint: Conclusion is also a premise.
    • Red Flag Indicators: Arguments that assume what they seek to prove, circular reasoning, or loaded questions that presuppose unproven assumptions.
    • Example: "I know the Bible is right because it comes from God, and I know God exists because the Bible proves it."
    • Logical Breakdown: The argument fails to supply independent evidence to prove the conclusion.
    • Loaded Question Subtype: Complex questions like "Why are you lying to me?" function as begging the question because they presuppose the unproven conclusion that the person is lying.

  • Equivocation

    • Status: Core Test Fallacy
    • Definition: Changing the operational meaning of a key term in the middle of an argument.
    • Key Hint: One word used in two different ways.
    • Red Flag Indicators: A identical word utilized with contrasting definitions, species-to-genus semantic shifts, or metaphorical-to-literal shifts.
    • Example: "Letter grades are a crude measure of performance. Therefore, students should not be graded [evaluated]."
    • Logical Breakdown: The validity of the reasoning is an illusion caused by verbal ambiguity.

  • Appeal to Ignorance

    • Status: Core Test Fallacy
    • Definition: Claiming a proposition is true simply because it has not been proven false, or false simply because it has not been proven true.
    • Key Hint: Something is not known / missing evidence.
    • Red Flag Indicators: Statements like "no one has proven otherwise" or treating a total absence of evidence as affirmative proof.
    • Example: "No one has proven that ghosts do not exist, so ghosts must exist."
    • Logical Breakdown: Lack of knowledge or disproof regarding one claim does not logically establish the truth of its opposite.

  • Diversion Overview

    • Core Concept: A diversion fallacy states a specific conclusion, but the supporting reasons logically direct attention toward an entirely different conclusion, leaving the original claim ungrounded.

  • Missing the Point

    • Status: Core Test Fallacy
    • Definition: Presenting premises that logically support a conclusion, but not the specific conclusion being asserted.
    • Key Hint: The evidence points to a different conclusion.
    • Red Flag Indicators: Offering macro-level or general evidence to prove a narrow, specific claim.
    • Example: "The Boeing 737 Max is safe because air travel in general is safe."
    • Logical Breakdown: Statistical safety trends for general aviation do not inherently establish the structural safety of a specific aircraft model.

  • Straw Man

    • Status: Core Test Fallacy
    • Definition: Rebutting a distorted, exaggerated, or oversimplified caricature of an opponent's argument instead of their actual position.
    • Key Hint: Distort the argument, then attack the distortion.
    • Red Flag Indicators: Responses beginning with "So you are saying…" followed by an extreme position the speaker never claimed.
    • Example:
    • Student: "We should have more class discussion."
    • Teacher: "We cannot turn the class into one endless discussion."
    • Logical Breakdown: Defeating a manufactured, weakened position fails to refute the original argument.

  • Red Herring

    • Status: Core Test Fallacy
    • Definition: Raising an irrelevant topic to distract attention away from the original issue under discussion.
    • Key Hint: Distraction.
    • Red Flag Indicators: Abruptly shifting topic focus to an unrelated emotional or interesting point when confronted.
    • Example:
    • Question: "Why did you miss the assignment?"
    • Answer: "I have been helping my friends a lot lately."
    • Logical Breakdown: The response may highlight positive or interesting information, but it fails to address the actual prompt.

  • Non Sequitur

    • Status: Core Test Fallacy
    • Definition: Asserting a conclusion that has no logical connection to the provided premises.
    • Key Hint: It does not follow.
    • Red Flag Indicators: Two completely disconnected ideas forced together as premise and conclusion.
    • Example: "Morgan State has a beautiful campus, therefore I will get an A in philosophy."
    • Logical Breakdown: Campus aesthetics carry zero logical bearing on academic performance in a specific course.

Fallacy Comparison & Distinction Guide

  • Hasty Generalization vs. Accident

    • Hasty Generalization: Moves from small, specific cases →\rightarrow broad general rule.
    • Accident: Moves from a general rule →\rightarrow specific case without acknowledging special exceptions.

  • Post Hoc vs. Slippery Slope

    • Post Hoc: Assumes past Event A caused past Event B simply because A occurred first.
    • Slippery Slope: Predicts a speculative future sequence of cascading disasters from a single initial action.

  • Straw Man vs. Red Herring

    • Straw Man: Distorts, exaggerates, or misrepresents the opponent's argument and refutes that distortion.
    • Red Herring: Ignores the opponent's argument and changes the subject entirely to distract.

  • Missing the Point vs. Non Sequitur

    • Missing the Point: The premises legitimately support a conclusion—just not the specific target conclusion.
    • Non Sequitur: The conclusion has no logical relationship to the premises whatsoever.

  • Subjectivism vs. Appeal to Majority

    • Subjectivism: "I personal believe/want it to be true."
    • Appeal to Majority: "Most people believe it to be true."

  • Begging the Question vs. Equivocation

    • Begging the Question: Circular argument where the conclusion is assumed in the premise.
    • Equivocation: Semantic manipulation where a key word shifts meaning mid-argument.

  • Ad Hominem vs. Straw Man

    • Ad Hominem: Attacks the opponent's personal traits, character, or motives.
    • Straw Man: Attacks a distorted version of the opponent's logical argument.

  • Appeal to Ignorance vs. Subjectivism

    • Appeal to Ignorance: "It has not been conclusively proven false, so it must be true."
    • Subjectivism: "I personally feel/desire it to be true."

Practice Exercises: Scenario Identification

  • Scenario 1: "I know I will pass the exam because I refuse to believe I could fail."

    • Fallacy: Subjectivism
    • Explanation: The argument bases its outcome on personal refusal to accept an uncomfortable thought rather than objective academic readiness.

  • Scenario 2: "Almost everyone in the dorm says that professor is unfair, so the professor definitely is unfair."

    • Fallacy: Appeal to Majority
    • Explanation: The claim relies on the number of dorm residents who agree rather than objective grading metrics.

  • Scenario 3: "You had better believe my claim about this policy, or I will make sure you are removed from the club."

    • Fallacy: Appeal to Force
    • Explanation: Coercion and threat of club expulsion are substituted for logical argument.

  • Scenario 4: "Do not listen to Maya's argument about budgeting. She is irresponsible and always loses her keys."

    • Fallacy: Ad Hominem (Abusive)
    • Explanation: Attacking Maya's personal habits and key-losing history avoids evaluating her actual financial reasoning.

  • Scenario 5: "My favorite rapper says this supplement improves memory, so it must improve memory."

    • Fallacy: Appeal to Authority / Bad Authority
    • Explanation: Treats a musical artist as an expert on dietary supplement efficacy without relevant credentialing.

  • Scenario 6: "Either you major in something that makes a lot of money or you will be unsuccessful in life."

    • Fallacy: False Dichotomy
    • Explanation: Unjustifiably limits life success to high-earning college majors, ignoring all other criteria and paths.

  • Scenario 7: "I changed my phone wallpaper, and then I got a job offer. The wallpaper brought me good luck."

    • Fallacy: Post Hoc
    • Explanation: Assumes the wallpaper caused the job offer solely because the wallpaper change preceded the offer.

  • Scenario 8: "Two students from that school were rude to me, so students from that school are rude."

    • Fallacy: Hasty Generalization
    • Explanation: Draws a broad conclusion about an entire student body based on an unrepresentatively small sample of two individuals.

  • Scenario 9: "It is generally wrong to break promises, so you must keep a promise even if keeping it would put someone in immediate danger."

    • Fallacy: Accident
    • Explanation: Mechanically applies a standard ethical rule to an extreme situation involving direct danger where an exception is warranted.

  • Scenario 10: "If the professor lets one student submit an assignment late, soon everyone will turn everything in late, deadlines will become meaningless, and the entire course will fall apart."

    • Fallacy: Slippery Slope
    • Explanation: Outlines an unevidenced chain reaction extending from a single late submission to total course breakdown.

  • Scenario 11: "This rule is fair because it is a fair rule."

    • Fallacy: Begging the Question
    • Explanation: Merely repeats the conclusion as its own supporting premise.

  • Scenario 12: "Feathers are light. What is light cannot be dark. Therefore, feathers cannot be dark."

    • Fallacy: Equivocation
    • Explanation: The term "light" shifts from defining physical weight to defining color illumination.

  • Scenario 13: "No one has proven that there is no life on that distant planet, so there must be life there."

    • Fallacy: Appeal to Ignorance
    • Explanation: Converts an absence of scientific disproof into affirmative proof of alien life.

  • Scenario 14: Claim: "This particular tutoring program improves PHIL 109 grades." Reason: "Tutoring in general can help students learn."

    • Fallacy: Missing the Point
    • Explanation: General evidence regarding tutoring in broad terms does not prove the specific effectiveness of one tailored program.

  • Scenario 15: Student: "I think we should have one extra review session before the test." Response: "We cannot spend the whole semester reviewing and never learn new material."

    • Fallacy: Straw Man
    • Explanation: Exaggerates a simple request for a single review session into an extreme claim to review continuously all semester.

  • Scenario 16: "Why are you cheating on your assignments?" (Asked prior to establishing evidence of cheating).

    • Fallacy: Begging the Question (Loaded Question)
    • Explanation: Embeds an unproven assumption of guilt directly into the question structure.

  • Scenario 17: Question: "Why did you miss class?" Response: "Well, I donate clothes every year and I am a really caring person."

    • Fallacy: Red Herring
    • Explanation: Shifts the topic to charitable donations to distract from answering why class was missed.

  • Scenario 18: "The library closes at 10 p.m. Therefore, my philosophy argument is valid."

    • Fallacy: Non Sequitur
    • Explanation: Library closing hours bear no logical connection to logical argument validity.

  • Scenario 19: "You cannot criticize me for being late because you were late last week too."

    • Fallacy: Ad Hominem (Tu Quoque)
    • Explanation: Accuses the critic of hypocrisy rather than addressing the lateness issue.

  • Scenario 20: "Of course the student senator supports the proposal. She only supports it because she wants votes, so her argument must be wrong."

    • Fallacy: Ad Hominem (Poisoning the Well)
    • Explanation: Dismisses the senator's argument based on presumed political motivation rather than evaluating the proposal's merits.

  • Scenario 21: "Every ingredient in this dish tastes good by itself, so the finished dish must taste good."

    • Fallacy: Composition (Homework Only)
    • Explanation: Assumes the combined whole must possess the same properties as its individual isolated ingredients.

  • Scenario 22: "Morgan State has many accomplished graduates, so every Morgan State student must be accomplished already."

    • Fallacy: Division (Homework Only)
    • Explanation: Attributes a general collective institutional statistic to every single individual student.

  • Scenario 23: "I was raised to believe that this tradition is correct, so it is correct."

    • Fallacy: Subjectivism
    • Explanation: Relies on personal upbringing and subjective belief as proof of objective truth.

  • Scenario 24: "Millions of people reposted the claim, so the claim must be accurate."

    • Fallacy: Appeal to Majority
    • Explanation: Equates social media repost volume with factual accuracy.

  • Scenario 25: "I studied with a blue pen before two exams and did well both times. The blue pen caused my high grades."

    • Fallacy: Post Hoc
    • Explanation: Assumes pen ink color caused test scores based strictly on chronological order.

  • Scenario 26: "I met one rude finance major today. Finance majors are rude."

    • Fallacy: Hasty Generalization
    • Explanation: Forms a sweeping generalization about an entire academic major based on a sample size of one.

  • Scenario 27: "If you skip one workout, you will lose your discipline, then stop exercising, then become unhealthy forever."

    • Fallacy: Slippery Slope
    • Explanation: Asserts without evidence that missing one workout leads linearly to permanent total health degradation.

  • Scenario 28: "The campus is large. Large fries have many calories. Therefore, the campus has many calories."

    • Fallacy: Equivocation
    • Explanation: Shifts the word "large" from physical geographic scale to food portion sizing.

  • Scenario 29: "No evidence has shown that Jamal cheated, so we know for certain that he did not cheat."

    • Fallacy: Appeal to Ignorance (Negative Form)
    • Explanation: Uses a lack of evidence proving guilt as absolute conclusive proof of actual innocence.

  • Scenario 30: Student: "Attendance should count for a little less of the grade." Response: "So you think students should be allowed to never come to class at all."

    • Fallacy: Straw Man
    • Explanation: Distorts a request to slightly reduce attendance weight into an extreme proposal to eliminate attendance requirements entirely.

Final 60-Second Memorization Sheet

  • Subjectivism: ME
  • Appeal to Majority: NUMBERS
  • Appeal to Force: THREAT
  • Ad Hominem: PERSON
  • Appeal to Authority: BAD EXPERT
  • False Dichotomy: ONLY 2
  • Post Hoc: BEFORE = CAUSE
  • Hasty Generalization: TOO FEW CASES
  • Accident: RULE →\rightarrow SPECIAL CASE
  • Slippery Slope: SMALL →\rightarrow DISASTER
  • Begging the Question: CIRCLE
  • Equivocation: WORD CHANGES MEANING
  • Appeal to Ignorance: NOT PROVEN
  • Missing the Point: PROVES SOMETHING ELSE
  • Straw Man: TWIST ARGUMENT
  • Red Herring: DISTRACT
  • Non Sequitur: DOES NOT FOLLOW
  • Homework Extras: Appeal to Emotion (3.1), Composition (3.2), Division (3.2). Designated for homework practice rather than primary test evaluation.