“It sort of makes you stop and think, doesn’t it”

2. “It sort of makes you stop and think, doesn’t it”

3. Why is it better to have round manhole covers than square ones?

4. Reason

5. Theory of Knowledge Diagram Mathematics Ways of Knowing Natural Sciences Reason Sense Perception Ethics Knower(s) Emotion Areas of Knowledge Language Human Sciences Arts History

6. Empiricism starting point for all knowledge is experience Rationalism starting point for all knowledge is reason TaK - Reason

7. Theory of Knowledge Diagram Mathematics Ways of Knowing Natural Sciences Reason Sense Perception Ethics Knower(s) Emotion Language Human Sciences Areas of Knowledge Arts History • What role does reason playin the different Areas of Knowledge?

8. What is meant by ‘Reason’? • 1. Reason(noun) • abasisorcause, as for some belief, action, fact, event, etc • 2. Reason(verb) • to think or argue in a logical manner; • to form conclusions or judgments from facts, propositions or premises (initial assumptions) TaK - Reason

9. Carl Sagan – Eratosthenes http://www.youtube.com/watch?v=G8cbIWMv0rI

10. A Story A businessman had just turned off the lights in the store when a man appeared and demanded money. The owner opened a cash register. The contents of the cash register were scooped up, and the man sped away. A member of the police force was notified promptly. Statements about the story (True/False/Uncertain) 1. A man appeared after the owner had turned off his store lights. 2. The robber was a man. 3. The man who appeared did not demand money. 4. The man who opened the cash register was the owner. 5. The store owner scooped up the contents of the cash register and ran away. 6. Someone opened a cash register. 7. After the man who demanded the money scooped up the contents of the cash register, he ran away. 8. While the cash register contained money the story does not state how much. 9. The robber demanded money of the owner. 10. The story concerns a series of events in which only three persons are referred to: the owner of the store, a man who demanded money, and a member of the police force. 11. The following events are true: Someone demanded money, a cash register was opened, its contents were scooped up, and a man dashed out of the store.

11. TaK - Reason There are three men on a train: one of them is an economist, one is a logician and one is a mathematician. They have just crossed the border into Scotland and they see a brown cow standing in a field from the window of the train. The cow is standing parallel to the train. The economist says, “Look! The cows in Scotland are brown”. The logician says, “No. There are cows in Scotland of which one, at least, is brown.” The mathematician says, “No. There is at least one cow in Scotland of which one side appears to be brown.”

12. TaK - Reason A dead body is lying in a field. He is carrying an unopened package. How did he die?

13. TaK - Reason “He that will not reason is a bigot*; he that cannot reason is a fool; and he that dares not reason is a slave” William Drummond 1585-1649 *Bigot: a prejudiced person who is intolerant of any opinions differing from their own

14. TaK - Reason Goya - The Sleep of Reason Produces Monsters 1798

15. Aristotle 384BCE – 322BCE TaK - Reason …. wrote that women have fewer teeth than men

16. Margaret Heffernan – Dare to disagree http://www.ted.com/talks/margaret_heffernan_dare_to_disagree.html

18. TaK - Reason Reasonenables us to go beyond the immediate evidence of our senses to acquire new knowledge The path is wet in the morning .... You left your mobile phone either on your desk or in your coat pocket ...

19. TaK - Reason A man is wearing black: black shoes, socks, trousers, coat, gloves and ski mask. He is walking down a back street with all the street lamps off. A black car is coming towards him with its lights off but somehow manages to stop in time. How did the driver see the man?

21. TaK - Reason You are presented with the following rule - Every card with a vowel on one side has an even number on the reverse side These are the cards: U G 7 2 Which 2 cards should be turned over in order to find out if this statement is true or false?

22. TaK - Reason You are a bar-person in a nightclub. The club has the following rule - Every person drinking alcohol must be over 20 years of age There are four situations: Person Drinking Beer Person Drinking Lemonade Person Aged 19 years Person Aged 21 years Which two situations should be investigated? http://skepticwiki.org/index.php/Wason's_Four-card_Task

23. TaK - Reason The two examples are formally identical. Why is it easier to spot the correct answers in the second example? Do your answers reflect something about human thinking in general?

24. TaK - Reason • Three kinds of Reasoning • Inductive reasoning • Deductive reasoning • Informal reasoning

25. TaK - Reason Inductive reasoning From the particular to the general (the observed to the unobserved) • This first bird can fly... • This second bird can fly... • This third bird can fly... • This fourth bird can fly... • This nth bird can fly... • Therefore all birds can fly.

26. TaK - Reason Science uses inductivereasoning: Formulates general laws on the basis of limited observations – • Metal A expands when heated • Metal B expands when heated • Metal C expands when heated • ..... a conclusion?

27. TaK - Reason Will the sun rise tomorrow? How do you know? How certain are you?

28. TaK - Reason • Problems with Induction: • Reasoning from the observed, to the unobserved • How many observations should be made before we jump to a generalisation?

29. TaK - Reason A murderer is condemned to death. He has to choose between three rooms: The first is full of raging fires, the second is full of assassins with loaded guns, and the third is full of lions that haven't eaten in 3 years. Which room is safest for him?

30. TaK - Reason There is a scene in a Broadway play where a guest at a party meets a Catholic priest. The guest asks, “Don’t you hear some terrible things in confession?” The priest replies, “Oh yes. In fact when i was just starting out as a priest, the first person who came to confession told me they had committed a murder.” Later on, a newcomer joins the party, and on being introduced to the priest says, “I met you a long time ago, Father. In fact I was the first person to come to you for confession.”

31. TaK - Reason Deductive reasoning From general to particular: • The first person who came to confession told the priest that he had committed a murder • The guest at the party was the first person to come to the priest for confession • Therefore the guest had committed a murder

32. TaK - Reason Deductive reasoning The Curious Incident of the Dog in the Night-time .... Sherlock Holmes

33. TaK - Reason The Curious Incident of the Dog in the Night-time .... Gregory (Scotland Yard detective): "Is there any other point to which you would wish to draw my attention?“ Holmes: "To the curious incident of the dog in the night-time.“ Gregory: "The dog did nothing in the night-time.“ Holmes: "That was the curious incident.” • Watchdogs bark at strangers • The watchdog did not bark at the thief • Therefore the thief was not a stranger

34. TaK - Reason Deductive reasoning From general to particular • All humans are mortal • Edmund is human • Therefore Edmund is mortal If the ‘assumptions’ are correct (which in Logic are called, ‘premises’) the conclusion has to follow. No if’s and but’s - it’s not a matter of personal opinion, nor is it affected by culture.

35. TaK - Reason Deductive reasoning From general to particular: • Two premises and a conclusion • Three terms – each occurring twice • Quantifiers (‘all’, ‘some’, ‘most’ etc) • This is formally called a Syllogism Term 1 Quantifier Term 2 • All humans are mortal • Edmund is human • Therefore Edmund is mortal Premise 1 Term 3 Premise 2 Conclusion

36. TaK - Reason Truth and Validity • Truth: concerned with what is the case • Validity: only concerned with whether conclusions follow from premises…..

37. TaK - Reason • All polar bears are footballers • Larry is a polar bear • Therefore Larry is a footballer • Valid argument – but not true • You should not say that an argument is true or false, but that it is valid or invalid.

38. TaK - Reason • 1. Argument(noun) • an oral disagreement; verbal opposition; contention; altercation: ‘a violent argument’ • 2. Argument(noun) • a process of reasoning; series of reasons: • ‘I couldn't follow his argument’

39. Premise (Claim) • Conclusion (Claim) TaK - Reason Argument Inference Argument Inductive Deductive Finds rules Applies rules • Watchdogs bark at strangers • The watchdog did not bark at the thief • Therefore the thief was not a stranger

40. TaK - Reason general Induction Deduction particular

41. TaK - Reason

42. TaK - Reason Inductive reasoning From the particular to the general (the observed to the unobserved) • I have never heard of a human being who didn’t die • ... then we generalise to ... • All human beings are mortal • Inductive Reasoning allows us to make generalisations about the world.

43. TaK - Reason What is a generalisation? • What distinguishes good generalisations? • Number – you see one dog swimming... • Variety – different circumstances; old dogs, young dogs, different breeds... • Exceptions– find counter-examples... • Coherence– you should demand more evidence to support surprising claims than unsurprising ones • Subject area – eg. generalisations tend to be more reliable in the natural sciences than in the social sciences

44. TaK - Reason • Give examples of some • hasty generalisations • Why do you think that people are so quick to jump to conclusions? • What is the difference between a prejudice and a generalisation?

45. TaK - Reason Bad reasoning • Ignorance • Laziness • Pride • Prejudice

46. TaK - Reason Informal reasoning Fallacies (invalid patterns of reasoning) • http://www.youtube.com/watch?v=fXLTQi7vVsI&feature=related

47. Informal reasoning • Yourposition: “I think . . .” • Your supporting proposition: “Because . . .” • Your supporting reasons: “As . . .” • Supportingevidence / facts: “Supported by . . .” • So, in the heat of the moment, someone arguing about President Obama might argue: • “I THINK President Obama is a great president” (POSITION) • “BECAUSEhe’s a great leader” (PROPOSITION) • “AShe listens to people and commands respect” (REASON) • “SUPPORTED BY the fact that he runs monthly town hall meetings where he answers people’s questions”(FACT)

48. TaK - Reason Informal reasoning – Fallacies (Invalid patterns of reasoning) • Post hoc ergo propter hoc – assume that because B follows A that A must be the cause of B • Ad hominem fallacy – attack or support the person rather than the argument • Circular reasoning – assume the truth of something you are supposed to be proving • Special pleading – making an exception in your own case that you would not find acceptable if it came from someone else • Equivocation – using language ambiguously • Argument ad ignorantium– claim that something is true on the grounds that there is no evidence to disprove it • False analogy – assume that because two things are similar in some ways that they must be similar in some further way • False dilemma – assume that only two alternatives exist when there are in fact a wide range of options • Loaded questions – a question that is biased because it contains a built-in assumption

49. TaK - Reason • Since strict gun controls were introduced in Dodge City, the crime rate has risen. This shows that gun control does nothing to reduce crime. • Jane said she trusted me, and she must be telling the truth because she wouldn’t lie to someone that she trusted. • The ends justify the means. After all, if you want to make omelettes, you have to break eggs. • Since the English always talk about the weather, if you meet someone who talks about the weather you can be sure they are from England. • Since many great scientists have believed in God, there must be some truth in religion. • We got on very well on both of our dates together. We are clearly well suited. Let’s get married! • Do you want to be part of the solution or part of the problem? • The average UK family has 2.4 children. The Smiths are very average people. Therefore they must have 2.4 children. • Since no-one has been able to prove that we are alone in the universe, we must conclude that other life forms exist. • Are all your family stupid, or is it just you? • No breath of scandal has ever touched the Senator. So he must be an honest man. • Just as you are more likely to take care of a car that you own than one that you rent, so a slave owner is more likely to take care of his slave than an employer is of his worker.