Fallacy

Formal fallacies have an identifiable error in the logical structure of the argument — such as affirming the consequent (if p then q; q; therefore p) — making the argument invalid regardless of content. Informal fallacies have errors in content, context, or relevance rather than structure, such as straw man (distorting the opponent's argument) or ad hominem (attacking the person instead of the argument).

Four causal fallacies are detailed: false cause (asserting causation where none exists, like the ice cream and drowning correlation), post hoc ergo propter hoc (confusing temporal sequence with causation, like a lucky charm causing exam success), slippery slope (claiming inevitable extreme consequences from a first step), and gambler's fallacy (believing independent event probabilities are affected by prior outcomes, like expecting tails after five consecutive heads).

The straw man fallacy involves misrepresenting or exaggerating an opponent's argument to make it easier to attack. The reference gives the example: Person A says "We should reduce gaming time," and Person B responds "So you want to ban all games?" — distorting a moderate position into an extreme one. The fallacy works because the distorted version is easier to argue against than the actual position.

The composition fallacy applies properties of individual parts to the whole (all players are excellent, therefore the team is excellent — ignoring that team performance depends on coordination). The division fallacy does the reverse, applying properties of the whole to its parts (America is wealthy, therefore all Americans are wealthy). Both involve incorrectly transferring attributes between different levels of analysis.

Several entries cover cognitive biases: survivorship bias (generalizing only from visible success cases while ignoring failures), the Texas sharpshooter fallacy (drawing the target around the bullet holes after shooting), cherry picking (selectively presenting favorable evidence), the conjunction fallacy/Linda problem (judging joint probability as higher than individual probability), and the gambler's fallacy (believing independent probabilities are influenced by prior events).

Appeal fallacies invoke emotions, threats, tradition, or pity instead of logical reasoning. The reference covers four: ad populum (appeal to emotion — "opposing this bill abandons our children's future"), ad baculum (appeal to force — threatening consequences for disagreement), appeal to tradition (arguing something is good because it is old), and ad misericordiam (appeal to pity — asking for a passing grade because one's family will suffer).

The false dilemma (also called black-and-white thinking or false dichotomy) artificially limits choices to only two options when more exist. The reference example is "You're either with us or against us," which ignores neutrality, partial agreement, or third-party positions. A related entry covers black-and-white thinking (if it's not 100% safe, it's not safe at all), which eliminates the spectrum between extremes.

Appeal to authority (argumentum ad verecundiam) uses a non-expert's authority as evidence — like citing a famous actor's endorsement of a health supplement. Appeal to ignorance (argumentum ad ignorantiam) claims something is true because it hasn't been proven false, or vice versa — like arguing aliens exist because no one has proven they don't. Both bypass the need for relevant evidence.