IMAT Logical Reasoning · Free notes
Critical Thinking: Arguments, Assumptions and Flaws
Critical Thinking has 119 past questions since 2011, and the ministry papers from 2023 on have asked 2 of them. Almost all of them come from the Cambridge papers, where each item was a short argument followed by one question about its conclusion, its hidden assumption, its flaw, or the fact that would make it stronger or weaker. No outside knowledge is needed: the work is reading closely and testing every option against the passage alone. The difficulty sits in the options, which reuse the passage's own words and differ from the right answer by one small step too far.
The handout has every subtopic, worked example, formula and trap with answers shown.
Subtopic notes
Parts of an Argument and the Main Conclusion
0 PYQsAn argument is a claim plus the reasons given for it; every critical thinking question starts by telling the two apart.
Drawing a Conclusion That Follows
0 PYQsA conclusion follows from a passage when the passage alone supports it, at exactly the strength the passage allows.
Hidden Assumptions and the Negation Test
0 PYQsAn assumption is an unstated premise the argument needs; deny it and the conclusion no longer follows.
Strengthening and Weakening an Argument
0 PYQsTake each option as true and ask whether it makes the step from reasons to conclusion more or less believable.
Identifying Flaws in Reasoning
0 PYQsA flaw is a mistake in the step from reasons to conclusion; IMAT asks you to name it in plain words.
Matching Structures and Applying Principles
0 PYQsStrip an argument down to its skeleton or its general rule, then find the option that shares it on a different topic.
Formula & revision sheet
0 formulas · 17 gotchas across all subtopics — the exam-eve cheat-sheet
Formula & revision sheet
0 formulas · 17 gotchas across all subtopics — the exam-eve cheat-sheet
Watch out for (3)
- 'Therefore' does not always mark the main conclusion→ Parts of an argument: premises, conclusions and indicator words
- The last sentence is not always the conclusion→ Identifying the main conclusion of an argument
- The intermediate conclusion is the favourite wrong answer→ Identifying the main conclusion of an argument
Watch out for (3)
- 'Some' does not mean 'not all'→ Quantifiers and the strength of a claim: all, most, some, may
- A true statement is not the same as a conclusion→ Drawing a conclusion that follows from a passage
- The dull option is often the right one→ Drawing a conclusion that follows from a passage
Watch out for (3)
- A stated premise is not an assumption→ Finding the hidden assumption by locating the gap
- Negating 'all' gives 'not all', not 'none'→ The negation test for assumptions
- Helpful is not the same as required→ The negation test for assumptions
Watch out for (2)
- Cost is rarely the weakener→ Weakening an argument: attack the link, not the facts
- On the topic is not the same as relevant→ Strengthening an argument: close the gap
Watch out for (4)
- A link is only a flaw when the conclusion claims a cause→ Causal flaws: correlation, reverse cause and ignored explanations
- A big sample can still be a biased sample→ Generalising from a small or unrepresentative sample
- 'Only if' introduces the necessary condition→ Confusing necessary and sufficient conditions
- Citing an expert is not automatically a flaw→ Other named flaws: attacking the person, straw man, false choice and more
Watch out for (2)
- Matching the topic is not matching the structure→ Matching arguments with the same structure
- Same topic, different principle→ Identifying and applying the principle behind an argument
PYQ weightage by concept
14 concepts · 0 PYQs — where the marks actually sit, so you know what to drill first
PYQ weightage by concept
14 concepts · 0 PYQs — where the marks actually sit, so you know what to drill first
| Concept | PYQs | Share |
|---|---|---|
| Parts of an argument: premises, conclusions and indicator wordsfoundation | — | — |
| Identifying the main conclusion of an argumentfoundation | — | — |
| Concept | PYQs | Share |
|---|---|---|
| Quantifiers and the strength of a claim: all, most, some, mayfoundation | — | — |
| Drawing a conclusion that follows from a passagefoundation | — | — |
| Concept | PYQs | Share |
|---|---|---|
| Finding the hidden assumption by locating the gapfoundation | — | — |
| The negation test for assumptionsfoundation | — | — |
| Concept | PYQs | Share |
|---|---|---|
| Weakening an argument: attack the link, not the factsfoundation | — | — |
| Strengthening an argument: close the gapfoundation | — | — |
| Concept | PYQs | Share |
|---|---|---|
| Causal flaws: correlation, reverse cause and ignored explanationsfoundation | — | — |
| Generalising from a small or unrepresentative samplefoundation | — | — |
| Confusing necessary and sufficient conditionsfoundation | — | — |
| Other named flaws: attacking the person, straw man, false choice and morefoundation | — | — |
| Concept | PYQs | Share |
|---|---|---|
| Matching arguments with the same structurefoundation | — | — |
| Identifying and applying the principle behind an argumentfoundation | — | — |