20 Logical Fallacies With ExamplesName the missing step, not the opponent
Bad arguments rarely arrive as nonsense. They arrive with a plausible premise, a vivid example, or a trusted voice, then ask it to carry a conclusion it cannot support.
That missing step is what a fallacy name should expose. Informal fallacies depend on context, and scholars do not share one final taxonomy: an expert's testimony can be relevant, emotion can matter to a moral argument, and a warning about cascading consequences can be well supported. The error begins when one of those moves is made to do work its evidence cannot carry.
The useful response is a complete sentence: “This conclusion does not follow because...” Each example isolates one bad inference; each diagnostic question helps finish that sentence before the label becomes a verdict.
ad hominem
rejecting a claim by attacking an irrelevant trait of the person making it
Example: Asked whether the budget assumptions hold, a director replies that the analyst has never managed a large team.
Test: If another person made the same argument, would the objection still answer it?
straw man
substituting a weaker or more extreme version of a position, then attacking that version
Example: A proposal asks for one meeting-free afternoon; its critic says the team wants to abolish collaboration.
Test: Would the other side recognize this as a fair statement of its actual claim?
false dichotomy
presenting two choices as exhaustive when other credible options exist
Example: Either the feature ships Friday or we concede the market, ignoring a limited release, a smaller scope, and a revised date.
Test: What third option appears if I separate the underlying goals from these two plans?
red herring
introducing an irrelevant issue that pulls attention away from the question under dispute
Example: Asked why customer data was retained past policy, an executive praises the security team's response time.
Test: What original question remains unanswered after this point is accepted?
slippery slope
asserting that a first step will trigger an extreme chain of consequences without supporting the links
Example: If contractors can attend one planning meeting, the critic predicts they will soon control the roadmap and the company.
Test: What mechanism makes each step likely, and where is the evidence for it?
circular reasoning
building a chain of support that eventually depends on the claim it was meant to establish
Example: The ranking is reliable because it uses trusted scores; the scores are trusted because they produce the ranking.
Test: Can I state a premise whose support does not lead back to the conclusion?
begging the question
smuggling the disputed conclusion into a premise instead of giving independent support
Example: The surveillance is justified because the company has a right to conduct necessary monitoring.
Test: Would someone who disputes the conclusion have any reason to accept the premise?
hasty generalization
drawing a broad conclusion from too few cases or an unrepresentative sample
Example: Two enterprise customers request exports, so a team concludes that every customer needs a reporting suite.
Test: How large and representative is the sample behind the general claim?
appeal to authority
treating status as proof when the cited authority lacks relevant expertise or adequate evidence
Example: A celebrity investor praises a medical supplement, so the advertisement calls its safety settled.
Test: Is this person expert in the exact question, and can I inspect the underlying evidence?
appeal to emotion
using an emotional response in place of support for a factual conclusion
Example: A moving customer story is offered as proof that a policy works across the whole population.
Test: After acknowledging the emotion, what evidence still connects the premises to the claim?
appeal to tradition
treating longevity as sufficient proof that a practice remains correct or useful
Example: The approval requires three signatures because it has required three signatures since the company was founded.
Test: What current purpose does the practice serve, apart from its age?
appeal to nature
inferring that something is good, safe, or right merely because it is described as natural
Example: A label calls an untested remedy plant-based and treats that description as its safety case.
Test: What property matters here, and does 'natural' establish that property?
tu quoque
deflecting a criticism by alleging that the critic is inconsistent or guilty of the same thing
Example: Asked to explain an undisclosed expense, a manager notes that the reviewer filed a late receipt last year.
Test: Even if the charge of hypocrisy is true, does it answer the original criticism?
loaded question
asking a question whose wording presupposes an unestablished or disputed claim
Example: When will the team admit that its redesign drove customers away?
Test: What must be accepted as true before any direct answer can be given?
equivocation
shifting a key word between different meanings while treating it as the same premise
Example: The service is free because sign-up costs nothing; therefore collecting and selling usage data imposes no cost.
Test: Can I replace the repeated word with a precise definition in every sentence?
composition fallacy
assuming a property of each part must also belong to the assembled whole
Example: Every screen is easy to understand in isolation, so the team assumes the complete workflow is easy to navigate.
Test: Could interactions among the parts change the property at the system level?
division fallacy
assuming every part inherits a property that belongs to the whole
Example: The portfolio had a strong return, so an adviser describes each asset inside it as a strong performer.
Test: Does the aggregate result conceal variation among its components?
post hoc
inferring that an earlier event caused a later one from sequence alone
Example: Sales rose after a logo change, so the rebrand gets credit despite a simultaneous price cut and seasonal demand.
Test: What comparison could separate this cause from timing, coincidence, and other changes?
no true Scotsman
protecting a generalization from counterexamples by redefining who counts as a genuine member
Example: No serious engineer skips this framework; when a respected engineer does, the reply is that she is not serious about scale.
Test: Was the membership rule changed only after a counterexample appeared?
cherry picking
selecting favorable evidence while withholding relevant evidence that points the other way
Example: A launch report quotes the two weeks with rising retention and omits the six weeks before and after them.
Test: What selection rule produced this evidence, and would it include an unfavorable result?
Reference: the Stanford Encyclopedia of Philosophy explains why familiar forms such as ad hominem and slippery-slope arguments can have reasonable instances, while OpenStax Introduction to Philosophy organizes common errors by relevance, weak induction, unwarranted assumption, and diversion.
The label should leave an argument better
Knowing twenty names can make any disagreement worse. The discipline is to set the name aside and point to the defect: the question went unanswered, an alternative disappeared, a term changed meaning, or sequence impersonated cause. If the argument can now be repaired, the label did its job. If the label merely replaced an argument, it became one more red herring.
Practice repairing the inference
Learn the names, then practice showing exactly which premise, definition, or inferential step still needs support.
Study logical fallacies