Critical Thinking

These are my notes from a course I took on Cirtical Thinking.

You can check out the course here : Critical Thinking in Global Challenges

The course is being offered by University Of Edinburg.

My Notes:

Essential elements of critical thinking

  • Fact – A demonstrable truth
  • Assertion – A statement which could be a fact (held true) but may not have been or could not be demonstrated to be true
  • Opinion – A personal opinion believed to be true by the speaker but may not be shared by others

Theory – Best attempt to explain something in the natural world based on what we currently know. Only as good as it corresponds with reality.
Good theory should be supported by evidence and must make testable predictions (called hypothesis) which can be verified as being correct pr incorrect

Argument : Series of logical stmts, leading to a fair conclusion, with reasons offered to support the conclusion
Valid Argument : based on 1 or more premises (starting pts), which may be facts, observations or assumptions
Strength of argument depends on evidence

An argument creates a set of premises and then based on sound logical reasoning generates a conclusion
Premises + Logical Reasoning -> Conclusion

Theory (Facts+Assertions+Opinions) .should result in a Testable Hypothesis (prediction)

Run theory against evidence ->

  • May support hypothesis and rule out (discard) other hypotheses
  • May lead to a new & revised hypotheses which can be tested again
  • May disprove the hypothesis, so the theory needs to be revised or discarded
  • May be inconclusive so that no firm conclusion can be made

Evidence is:

  • Fact
  • Experimental result

Evidence primary sources:

  •  Peer reviewed journal
  •  Artefact
  •  Experimental Data

Evidence secondary sources:

  •  Blog
  •  Magazine
  •  Documentary
  •  Books

Is the evidence:

  • Relevant
  • Accurate
  • Representative

For Assessing Evidence, verify following:

  • Provenance (primary or secondary)
  • Context
  • Authorship
  • Nature fact or opinion
  • Accuracy
  • Authority who is saying. Is the view shared

Steps For Assessing an argument :

1. Structure
Identify evidence and conclusion
2. Clarity
Find ambiguities, vagueness
3. Evidence
Assess evidence
4. Logic
Check for fallacies
5. Evaluate


  • Informal fallacy – the content of argument may be correct but there are mistakes in related logics
  • Formal fallacy – The logic of content of argument is wrong

Examples of Informal Fallacies:

  1. Ad hominem – Attacking the person instead of argument
  2. False dilemma – giving few options as if they are the only options – to reduce weight either u should exercise or undergo liposuction
  3. Correlation proves causation
  4. Cherry picking – picking favorable args and ignoring others
  5. Appeal to motive- questioning the motive of person making the argument
  6. Appeal to emotion – Using emotional appeal to prove an argument
  7. Straw man – Misrepresenting someone’s argument