Logical Fallacies and Common Reasoning Errors: Ad Hominem, Straw Man, False Dilemma, Hasty Generalisation and More for SSC
Rahul Kumar
SSC Exam Expert & Content Editor
In this note
PDF Notes: Logical Fallacies and Common Reasoning Errors: Ad Hominem, Straw Man, False Dilemma, Hasty Generalisation and More for SSC
Premium PDF · one-time payment of ₹5 · instant access
A fallacy is an error in reasoning that makes an argument look convincing but weak. Spotting fallacies is the core skill in questions on arguments, assumptions and flaws in the SSC reasoning section and in the critical reasoning questions of the other exams. This guide on logical fallacies for SSC explains the common fallacies with examples, tips and practice questions with answers.
Types of Fallacies
Fallacies are formal (error in the structure of the argument) or informal (error in the content, language or relevance). The ones asked in exams are mostly informal.
Common Informal Fallacies
| Fallacy | Meaning | Example |
|---|---|---|
| Ad hominem (attack on the person) | Attacking the person instead of the argument | He suggests saving water, but he is a failed businessman, so we should ignore him. |
| Straw man | Misrepresenting the opponent’s view to attack it easily | He wants a limit on the loudspeakers. He wants to ban all festivals. |
| Appeal to authority | Accepting a claim only because an authority said it, outside his field | A famous cricketer says this herbal tonic cures all diseases, so it must be true. |
| Appeal to popularity (bandwagon) | A claim is true because many people believe it | Millions use this app, so it must be the best. |
| Appeal to emotion (pity, fear) | Using feelings in the place of reasons | Please pass me; my family will be heartbroken otherwise. |
| False dilemma (either-or) | Presenting only two options when more exist | Either you support this plan or you are against the nation. |
| Slippery slope | Claiming that one step will lead to an extreme result without proof | If students are allowed one day of leave, soon nobody will attend the school. |
| Circular reasoning (begging the question) | The conclusion is assumed in the premise | This book is true because it says so itself. |
| Hasty generalisation | Drawing a general conclusion from a small or biased sample | Two of my cousins from that city are rude, so all people of that city are rude. |
| Post hoc ergo propter hoc | Assuming that because B followed A, A caused B | I wore my lucky shirt and we won, so the shirt made us win. |
| Red herring | Introducing an irrelevant issue to divert attention | Why talk about the pollution by factories when the people do not even vote? |
| False analogy | Comparing two things that are not alike in the relevant ways | A country is like a household, so it should never borrow. |
| Equivocation | Using a word with two meanings in the same argument | A feather is light; what is light cannot be dark; so a feather cannot be dark. |
| Non sequitur | The conclusion does not follow from the premises | He is tall, so he must be a good singer. |
| Tu quoque (you too) | Defending oneself by pointing to the opponent’s fault | You tell me not to litter, but you also did it last year. |
| Appeal to ignorance | Claiming something is true because it has not been proved false | No one has proved that ghosts do not exist, so they exist. |
| Fallacy of composition | What is true of the parts is true of the whole | Every player is excellent, so the team must be the best. |
| Fallacy of division | What is true of the whole is true of each part | The school is the best in the city, so each teacher is the best. |
| Cherry picking | Using only the evidence that supports the view and ignoring the rest | Quoting only the two good reviews out of fifty. |
How to Identify a Fallacy: Questions to Ask
- What is the conclusion, and what are the reasons given for it?
- Are the reasons relevant to the conclusion, or do they attack the person or distract?
- Is the evidence enough (sample size, source, other causes)?
- Is a hidden assumption being used that may not be true?
- Are there other possible options or explanations that the argument ignores?
Fallacies in Cause and Effect
- Post hoc: mistaking the sequence for the cause.
- Correlation and causation: two things occurring together do not mean that one causes the other (ice cream sales and drowning both rise in summer because of the heat).
- Single cause fallacy: giving one cause for an event that has many causes.
- Reverse causation: mixing up the cause and the effect.
Solved Examples
Example 1. “The new tax policy is wrong because the minister who proposed it was once accused of tax evasion.” Which fallacy is this?
Ad hominem.
Example 2. “Either we build the dam or the whole region will starve.” Which fallacy is this?
False dilemma.
Example 3. “After the new principal joined, the results fell. So the principal is the cause.” Which fallacy is this?
Post hoc ergo propter hoc (also a single-cause fallacy).
Example 4. “A person is honest because he never lies, and we know that he never lies because he is honest.” Which fallacy is this?
Circular reasoning.
Example 5. “A survey of 20 people shows that people of this state like cricket the most, so the whole state does.”
Hasty generalisation.
Quick Tips
- Learn each fallacy with a one-line example.
- Ask whether the reason is relevant to the conclusion.
- Check the sample size and the source in the statements about the evidence.
- Remember that correlation is not causation.
Quick Revision Points
- Ad hominem attacks the person, not the argument.
- Straw man distorts the opponent’s argument.
- False dilemma gives only two options.
- Post hoc confuses sequence with cause.
- Circular reasoning assumes the conclusion.
Practice Questions With Answers
- Which fallacy attacks the speaker instead of the argument?
Answer: Ad hominem - Which fallacy presents only two options when there are more?
Answer: False dilemma - Which fallacy draws a general conclusion from a very small sample?
Answer: Hasty generalisation - Which fallacy assumes that because B followed A, A caused B?
Answer: Post hoc ergo propter hoc - Which fallacy uses the conclusion as a premise?
Answer: Circular reasoning - Which fallacy introduces an irrelevant topic to divert attention?
Answer: Red herring - Which fallacy distorts the opponent’s argument?
Answer: Straw man - Which fallacy claims that something is true because many people believe it?
Answer: Appeal to popularity - Which fallacy claims that a statement is true because it has not been disproved?
Answer: Appeal to ignorance - Which fallacy is: every member is good, so the group is good?
Answer: Fallacy of composition
How to Practise This Chapter
Practise 10 questions every day and write the steps on paper. Then attempt timed sets from our practice papers and the previous year papers page. See all topics on the Logical Reasoning notes page, read the previous topic Deductive and Inductive Reasoning and the next topic Propositions, Truth Tables and Logical Connectives.
Frequently Asked Questions
What is a fallacy?
An error in reasoning that weakens an argument.
What is ad hominem?
Attacking the person making the argument instead of the argument.
What is a straw man fallacy?
Misrepresenting someone’s view so that it can be attacked easily.
What is a false dilemma?
A fallacy that treats only two options as possible when there are more.
What is a slippery slope?
Claiming without proof that a small step will lead to a chain of bad events.
What is circular reasoning?
An argument whose conclusion is already assumed in the premises.
What is a hasty generalisation?
A conclusion based on too little evidence.
What is post hoc ergo propter hoc?
The error of assuming that what follows an event was caused by it.
What is a red herring?
An irrelevant point used to divert the discussion.
Is this topic asked in SSC?
Yes. It helps in the statement, argument and assumption questions.
What is the difference between correlation and causation?
Two things may occur together without one causing the other.
What is equivocation?
Using a word in two different meanings in an argument.
Previous chapter
Deductive and Inductive Reasoning: Valid and Invalid Arguments, Modus Ponens, Modus Tollens and Examples for SSC Exams
Next chapter
Propositions, Truth Tables and Logical Connectives: Implication, Contrapositive, Converse and Necessary and Sufficient Conditions for SSC
Rahul Kumar
SSC Exam Expert & Content Editor
Rahul is a senior SSC exam strategist with 8+ years of experience helping aspirants crack CGL, CHSL and MTS exams. He writes in-depth notification breakdowns, exam pattern guides and preparation strategies.