1. ARGUMENTATION AND LOGIC
TOK LAJM

2. TASK Choose some thing that is important to you
E.g. a hobby, an athlete, an artist or a band
Try give reasons to your neighbour(s) why the thing you chose is good
Write down your reasons

3. TASK What were you actually trying to do in the previous task?
You were trying to give an argument!

4. What is an argument?
All arguments must have a main point and reason(s) that support it

5. What is an argument? (P1) Elvis had a distinctive voice
PREMISE(S) (P1–Pn)
– reasons of an argument that support the main point
(P1) Elvis had a distinctive voice
REASONING
(P2) Elvis gave huge concerts
(C) Elvis was a great artist
CONCLUSION (C)
– the main point of an argument

6. TASK Transform your argument into the following form:
Premises (P1–Pn)
Conclusion (C)
Write down your argument accurately
Evaluate your reasoning

7. What makes up a good argument?
(1) All the premises are true
(2) Premises support the conclusion i.e. reasoning is not flawed
PLEASE NOTE! Premises can be true or false, but an argument cannot be true or false
Argument can be good or bad

8. Truth and validity Truth Validity
What is the case?
Property of the premises
Validity
Does the conclusion follow from the premises?
Property of the reasoning process
The validity of an argument is independent of the truth or falsity of the premises it contains

9. Deductive reasoning
The truth of the premises guarantees the truth of the conclusion
The conclusion must necessarily follow from the premises
Logically valid

10. Deductive reasoning (P1) All men are mortal (P2) Elvis is a man
(C) Elvis is a mortal

11. TASK Evaluate the deductive arguments in the teacher’s handout
Are the deductive arguments logically valid or not and why?

12. Two forms of logically VALID deductive arguments
MODUS PONENS
MODUS TOLLENS
(P1) If A, then B
(P2) A
(C) B
(P1) If A, then B
(P2) not B
(C) not A

13. Two forms of logically INVALID deductive arguments
DENYING THE ANTECEDENT
AFFIRMING THE CONSEQUENT
(P1) If A, then B
(P2) not A
(C) not B
(P1) If A, then B
(P2) B
(C) A
ERROR!
ERROR!

14. Inductive reasoning
The truth of the premises makes the conclusion probable
The conclusion doesn’t necessarily follow from the premises
Statistical generalizations

15. Inductive reasoning (P1) I’ve seen thousands of ravens
(P2) All the ravens I’ve seen have been black
(C) All the ravens are black

16. TASK How to make good inductive arguments? Number of instances
What distinguishes good generalizations from bad ones?
Number of instances
Variety of circumstances
Exceptions, counter-examples
Coherence
Subject area, AOK

17. Argument of best explanation
Abductive reasoning
Reasoning from the available sources to the best possible explanation
Argument of best explanation

18. Abductive reasoning
(P1) A man was found dead in a remote cabin (P2) All the doors and the windows were shut from inside (P3) The man was hanging from a rope (C) The man had committed a suicide

19. Key principles in abduction
Simplicity
Consistency
Testability
Coverage

20. Induction and abduction
Induction and abduction can overlap
In searching for the best possible explanation, statistical generalizations and probabilities based on those generalizations can be used
In both cases the premises do NOT guarantee the truth of the conclusion
The premises just make the conclusion more likely or warranted

21. Fallacy An invalid pattern of argument, an error in reasoning
May occur in any type of reasoning

22. GROUP WORK How can our reasoning be flawed? Form five groups
Define and create examples of the most common fallacies with the help of the teacher’s instructions
Compile a short presentation for others

23. A critical thinker
Is aware of different ways of argumentation and various fallacies
Uses source criticism
Pursues intellectual integrity

25. CARS checklist

26. TASK
What are the ways of knowing argumentation and logic can relate to?
What are the areas of knowledge argumentation and logic can relate to?

27. TASK
Is there a way of knowing, area of knowledge or area of life where rational argumentation cannot be applied?

28. Picture Sources
Usain Bolt in Rio < Accessed 24th of August 2016.
Cartoon argument 1 < Accessed 24th of August 2016.
Cartoon argument 2 < Accessed 5th of April 2016
Argument as a house < Accessed 5th of April 2016

29. Picture Sources
Weapons of Mass Deduction < Accessed 19th of June 2016.
Elvis < Accessed 24th of August 2016.
Sherlock Holmes < Accessed 19th of June 2016.
Raven < Accessed 24th of August 2016.
Albino raven < Accessed 24th of August 2016.

30. Picture Sources
Sherlock Holmes and doctor Watson < Accessed 5th of August 2016.
Sherlock Holmes’ silhouette < Accessed 5th of August 2016.
Sherlock Holmes playing the violin < Accessed 5th of August 2016.
Logical fallacy meme < Accessed 25th of August 2016.
Don’t raise your voice, improve your argument < Accessed 15th of April 2016.

31. Picture Sources
Demand evidence and think critically < Accessed 25th of August 2016.
Questions a critical thinker asks < Accessed 18th of August 2016.
6 critical questions < Accessed 18th of August 2016.
CARS Checlist van de Lagemaat, Richard: Theory of Knowledge for the IB Diploma, Second edition, Cambridge University Press 2015, page 69
TOK curriculum < Accessed 2nd of August 2016.
Be rational – get real < Accessed 29th of August 2016.