![](https://www.youtube.com/watch?v=IoBbcU7ofZc) ## Description To try everything Brilliant has to offer for free for a full 30 days, visit https://brilliant.org/jaredhenderson. You’ll also get 20% off an annual premium subscription. If you want to support my work, subscribe on Substack: https://jaredhenderson.substack.com Today we're talking about logical fallacies. These are common patterns of reasoning cause us to make mistakes in how we argue or think about the world. Examples include: ad hominem, appeal to ignorance, and the gambler's fallacy. Join my Discord server: https://discord.gg/xq6wDUtdyQ → Video Gear Mic: https://amzn.to/3Uw7ZVw Recorder: https://amzn.to/3Tz1uQp Camera: https://amzn.to/3Ust3MT Camera (upgrade): https://amzn.to/3EFGW4e Lens: https://amzn.to/3WXbAhd Lens (upgrade): https://amzn.to/3SA49KM These are affiliate links with Amazon. The channel earns a commission from each purchase — but it doesn't cost you anything. ## My Notes %% [Fix YouTube Links w/ regexr.com](regexr.com/8c604) %% ### Introduction [00:00-00:29] - A logical fallacy is a pattern of reasoning that: - Weakens arguments - Is an unreliable guide to truth - Leads to bad inferences - Learning fallacies helps with: - Studying philosophy - Getting better at arguments ### Common Logical Fallacies #### [[Ad Hominem]] [00:29-00:52] - Attacking the person instead of addressing their argument - Using an insult as the basis for concluding someone is wrong - Note: Just insulting someone isn't automatically an ad hominem #### [[Appeal to Authority]] [00:52-02:24] - Deferring to power or expertise instead of making direct arguments - Two types: - Appealing to authority with power (e.g., President) - Appealing to expert opinion without considering evidence - Problems with this approach: - Experts are not infallible - Expert consensus can be wrong (e.g., doctors once thought cigarettes were harmless) - Conflicting authorities often disagree - We should evaluate arguments and evidence, not just authority #### [[Appeal to Emotion]] [02:24-03:11] - Stirring up feelings to convince people rather than using logic - Can be both positive and negative emotions - Variations include: - [[Appeal to Fear]] - [[Appeal to Flattery]] - [[Appeal to Hatred]] - [[Appeal to Love]] - [[Appeal to Guilt]] - [[Appeal to Pity]] #### [[Appeal to Popularity]] [03:11-03:46] - Justifying beliefs based on how many people hold them - Also called the [[Bandwagon Fallacy]] - Popular beliefs can be (and often are) false - Example: It was once widely believed the sun orbited Earth #### [[Appeal to Heterodoxy]] [03:46-04:19] - Taking disagreement as evidence of correctness - Positioning oneself as a "bold truth-teller" - Seeing lack of agreement as evidence for one's beliefs - The number of people who agree/disagree is irrelevant to truth ### Value of Studying Logical Fallacies [04:19-05:12] - When learning a new skill, we need: - Positive examples to emulate - Negative examples to avoid - Logical fallacies are negative examples - Studying logic helps identify valid arguments #### [[Appeal to Tradition]] [06:13-06:38] - Assuming something is true because it's old or traditional - Traditional beliefs can be false - Some may argue traditions survive because they're likely true, but this isn't logically guaranteed #### [[Appeal to Novelty]] [06:38-06:50] - Believing something is true because it's new - The inverse of appeal to tradition - Many new beliefs are also false #### [[Appeal to Progress]] [06:50-07:07] - Believing whatever will be believed in the future - Problem: People in the future can also be wrong #### [[Appeal to Hypocrisy]] [07:07-07:35] - Arguing someone is wrong because they're a hypocrite - A moral failure doesn't invalidate logical truth - Example: Someone who lies can still correctly claim lying is wrong #### [[Moralistic Fallacy]] [07:35-07:42] - Thinking what is desirable must be true #### [[Doomsayer Fallacy]] [07:42-07:51] - Thinking what is undesirable must be true - The inverse of the moralistic fallacy #### [[Appeal to Moderation]] or [[Middle Ground Fallacy]] [07:51-08:19] - Assuming the truth must be between two extreme positions - Extreme proposals can be correct - Moderate proposals can be correct - Extremity or moderation doesn't determine truth #### [[Appeal to Ignorance]] [08:19-08:47] - Assuming something is true because it hasn't been disproven - Example: Russell's teapot orbiting the sun #### [[Genetic Fallacy]] [08:47-09:06] - Judging a belief based on its origins - Origins of beliefs have little to do with their truth value #### [[Guilt by Association]] [09:06-09:16] - Dismissing beliefs because of others who hold them ### Probability-Related Fallacies #### [[Gambler's Fallacy]] [09:16-09:42] - Believing past random events affect future probabilities - Example: A coin landing heads 99 times doesn't change the 50% probability on the 100th flip #### [[Hasty Generalization]] [09:42-10:04] - Generalizing from too small a sample - Example: Seeing two white dogs and concluding all neighborhood dogs are white #### [[Hot Hand Fallacy]] [10:04-10:19] - Assuming past success with random events predicts future success - If events are truly random, past success doesn't indicate future success ### Formal Logical Fallacies [10:19-10:48] - Unlike informal fallacies, these relate to logical operators - Involve Boolean operators: if, and, or, not #### [[Affirming the Consequent]] [10:48-11:06] - If A then B; B, therefore A - Example: If it's raining, the sidewalk is wet. The sidewalk is wet, so it must be raining. - Problem: Other things can cause a wet sidewalk #### [[Denying the Antecedent]] [11:06-11:20] - If A then B; not A, therefore not B - Example: If it's raining, the sidewalk is wet. It's not raining, so the sidewalk isn't wet. - Problem: The sidewalk could be wet for other reasons #### [[Begging the Question]] [11:20-11:31] - Assuming what you're trying to prove - Including your conclusion in your premises #### [[Equivocation]] [11:31-12:06] - Using the same word with different meanings in an argument - Example: "Every law requires a lawgiver. There are laws of nature. Therefore, nature has a lawgiver." - Problem: "Law" means different things in each premise #### [[Straw Man]] [12:06-12:31] - Misrepresenting someone's position to make it easier to attack - Similar to equivocation between the real position and the misrepresentation #### [[No True Scotsman]] [12:31-13:05] - Dismissing counter-examples by redefining terms - Example: "No Scotsman puts sugar on porridge." "I'm Scottish and I do." "Well, no TRUE Scotsman does." #### [[Motte and Bailey]] [13:05-13:56] - Switching between two positions: - A radical position (bailey) - An easily defensible position (motte) - Example: "Defund the police" shifting between complete defunding and reallocating some funding #### [[Slippery Slope]] [13:56-14:31] - Assuming a minor change will lead to extreme consequences - Only a fallacy when lacking evidence for the chain of events - Sometimes incremental changes do lead to larger ones #### [[Correlation vs. Causation]] [14:31-14:45] - Assuming correlation implies causation - Two events happening together doesn't mean one causes the other #### [[Fallacy of Composition]] [14:45-15:08] - Assuming what's true of parts is true of the whole - Example: All cells in the body are microscopic, but the body isn't microscopic #### [[Fallacy of Division]] [15:08-15:15] - Assuming what's true of the whole is true of all parts - The inverse of the fallacy of composition #### [[Comparative Fallacy]] [15:15-15:27] - Inferring an absolute claim from a comparative claim - Example: A Rolex is cheaper than a Patek Philippe, but that doesn't mean a Rolex is cheap ### Conclusion [15:27-15:39] - Acknowledges some fallacies may have been omitted - Invites viewer discussion ## Transcript [Take interactive transcript notes on youtube-transcript.io](https://www.youtube-transcript.io/videos/IoBbcU7ofZc)