2. logic and epistemology, chs. 7 8, p. 94-132


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2. logic and epistemology, chs. 7 8, p. 94-132

  1. 1. TOK Chs. 7-8, p. 94-132Team 1: 94-100Team 2: 101-106Team 3: 107-113Team 4: 114-120Team 5: 121-127Team 6: 128-132 Week 2: Logic and Epistemology TOK, p. 115-132 Selected Readings
  2. 2. Where we are Going?• Blog 1: Gun Control Argue Out Teams (10 Minutes)• Notes: Ch.1-3 (18 min., 3 min. each)• Finish Week 1: – What is a Knower? – Intro to Ways of Knowing• Start Week 2: – Activity 3: Witch Trial – Laws of Logic – Formal and Informal – Fallacies – Blog 2: Fallacies
  3. 3. Loftus and Palmer (1974)• Elizabeth Loftus investigated the interaction between language, memory and eyewitness testimony.• Conclusions: – The way a question is worded often leads to a new reconstruction of a memory – Eyewitness testimony and estimations are often a dependent variable. – What other factors contribute to memory dependancy?
  4. 4. Memory• Memory and testimony are the cognitive foundation of the "knower" – Neurologically, memories are chemical reactions resulting from synapse activation within the brain. – Rationally, memories are the calculator and "rulebook" that allows for proper and logical thinking. – Emprically, memories are the record of our senses reconstructed through will or by outside stimulai – Pragmatically, memories are the priorities of the world in which p;ersonal meaning is constructed.• Do we have memories of the way things are, or is there always personal bias? Do our senses create accurate pictures of reality?
  5. 5. The Ways of Knowing• Reason – Analytic and synthetic – a priori or a posteriori – constructs of logic that define a thing or to define basic laws using symbolacrae• Sense Perception – Correspondance testing between memory and seeing, etc. – Basis for scientific philosophy. – Often subjective and vulnerable to bias. see aesthetic philosophy.• Intuition/imagination (?) – Memories reconstructed often with disregard for the backward looking sense perception and/or rationality to project to future events, develop innovative hypothesis, or to be a great artist.
  6. 6. The Ways of Knowing• Language – The symbols that connect our thoughts to others – Intrinsically indirect and requires assumptions about the world (such as the existence of other minds). – Often can present challenges to synergy of information• Emotion – The personal reaction and cultural parameters of expression connecting to others by thou
  7. 7. Tests of “Truthiness”• Correspondence – Statements are true so much as the relate to actual, observable data from the world. • “The snow is white”• Coherence – Statements are true so much as they are logically consistent with previous beliefs about the world. • “there are no pink elephants in Lake Elsinore because I know elephants are gray, live in africa…etc.”• Pragmatic – A statement is true if +it allows you to interact effectively and efficeintly with the cosmos. • “My belief that inanimate objects do not spontaneously get up and move about is true because it makes my world more predictable and thus easier to live in. It “works”
  8. 8. Testimony or Knowledge by Authority• Information about the world often comes through degrees of testimony – Data is received, passed, written, consolidated, taught, and recited.• How might the “authority fallacy” be different than “knowledge by authority?”• List 10 things you know by authority• List 10 things you know by personal testimony.
  9. 9. Knowledge Prism Knower • Knowledge is reliant upon various presuppositions: Proofs and Truth TestsEmpirical Observation – Rationality, laws of logic, and language can be used consistently and with meaning – Statements and observations can be investigated against counter-factuals to correspond some semblance of “external world” and “the way things really are” – An identity and mind to process, articulate, and construct a worldview based on observation and truth statements. Rationality
  10. 10. Rational and Empirical• What is the difference between the following phrases?: – “2+2=4” – “This cat is orange.” – “I was probed by an alien last night.”• Rationality: intuited propositions deduced towards knowledge. – A priori knowledge• Empiricism: Knowledge and concepts needed for knowledge come from our senses and perception. – A posteriori knowledge
  11. 11. Plato: “Justified True Belief”• Knowledge, according to Plato, has three parameters: – Justified: Is a truth claim in the realm of falsifiability? – True: is there enough evidence or reasonable argument for its probable correctness? – Belief: do I internalize and assume the claim into my worldview and understanding
  12. 12. Acquaintance vs. Description• “If you can’t say it, you don’t know it” – Hans Reichenbach (German philosopher of science, 1891-1953)• “I know more than I can say.” – Michael Polanyi (Hungarian philosopher of science, 1891-1976)
  13. 13. Imagination• “I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.”• “Everything you can imagine is real”• “We are what we pretend to be, so we must be careful about what we pretend to be.”• Can Imagination be a source of knowledge? What would its limits be? Can you know something that is only feasible in your mind?
  14. 14. TOK Chs. 7-8, p. 94-132Team 1: 94-100Team 2: 101-106Team 3: 107-113Team 4: 114-120Team 5: 121-127Team 6: 128-132 Week 2: Logic and Epistemology TOK, p. 94-132 Selected Readings
  15. 15. Activity 3: The Illogical Game• Watch the following clip from Monty Python’s Quest for the Holy Grail• Identify 5 statements that “don’t add up” based on your prior knowledge and common sense• In teams of four, see if you can identify the formal and informal fallacies behind your statements. List them out. – If you don’t know the names, try and describe/explain why they are illogical.
  16. 16. Break down of the Argument1. All witches are things that can burn.2. All things that can burn are made ofwood.3. Therefore, all witches are made ofwood. (from 1 & 2)4. All things that are made of wood arethings that can float.5. All things that weigh as much as a duckare things that can float.6. So all things that weigh as much as aduck are things that are made of wood.(from 4 & 5)7. Therefore, all witches are things thatweigh as much as a duck. (from 3 & 6)8. This thing is a thing that weighs as muchas a duck.9. Therefore, this thing is a witch. (from 7 &8)
  17. 17. Laws of Logic• 1. Law of identity. – Everything is what it is. A is A or A is Identical with A.• 2. law of Contradiction. – A cannot be A and not A at the same time.• 3. Law of Exculded Midddle. – A is either a or not A
  18. 18. Formal Logic• Syllogism – Two statements that create conditions towards and absolute conclusion statement.• Distribution – A line in logic that is properly moving from specific to general (i.e. all cats are mammals) based on language.• Modus Ponus – Form of logical reasoning that forms the basis of all formal logic
  19. 19. Deductive Reasoning• Taking general statements of truth about the world and reasoning towards a specific conclusion.• Formal logical constructs like the modus ponens are deductive
  20. 20. Inductive Reasoning• Inductive reasoning is perhaps the opposite of deduction• One takes specific statements and arrives at a general conclusion/principle• Which is more scientific?
  21. 21. Formal Fallacies• Affirmative conclusion from a negative premise (illicit negative) – when a categorical syllogism has a positive conclusion, but at least one negative premise.• Fallacy of exclusive premises – a categorical syllogism that is invalid because both of its premises are negative.• Fallacy of four terms (quaternio terminorum) – a categorical syllogism that has four terms.
  22. 22. Formal Fallacies• Illicit major – a categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion.• Illicit minor – a categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion.
  23. 23. Formal Fallacies• Negative conclusion from affirmative premises (illicit affirmative) – when a categorical syllogism has a negative conclusion but affirmative premises.• Fallacy of the undistributed middle – the middle term in a categorical syllogism is not distributed.
  24. 24. Quick Application1. If its raining, Ill • Modus Ponens meet you at the movie theater.2. Its raining.3. Therefore, Ill meet you at the movie theater.
  25. 25. Quick Application• If the cake is made • Modus Tollens with sugar, then the cake is sweet. The cake is not sweet.• Therefore, the cake is not made with sugar.
  26. 26. Quick Application• Either the Sun orbits • Disjunctive Syllogism the Earth, or the Earth orbits the Sun. The Sun does not orbit the Earth. Therefore, the Earth orbits the Sun.
  27. 27. Quick Application• Everyone who • Reasoning by drives at 80 MPH is Transivity speeding• All who speed P->Q break the law. Q->R• Therefore, everyone ______ who drives at 80 MPH breaks the Law Therefore: P->R
  28. 28. Quick Application• No fish are dogs, and • Affirmative no dogs can fly, conclusion therefore all fish can fly. • If A ⊄ B and B ⊄ C the n A ⊂ C.• We dont read that trash. People who read that trash dont appreciate real literature. Therefore, we appreciate real literature.
  29. 29. Quick Application• No mammals are • Fallacy of exclusive fish. premies• Some fish are not • No X are Y. whales. • Some Y are not Z.• Therefore, some • Therefore, some Z whales are not are not X. mammals.
  30. 30. Quick Application• All fish have fins. • Fallacy of four terms• All goldfish are fish.• All humans have fins.
  31. 31. Quick Application• All dogs are • Illicit major animals.• No cats are dogs.• Therefore, no cats are animals.
  32. 32. Quick Application• All cats are felines. • Illicit minor• All cats are • All A are B. mammals. • All A are C.• Therefore, all • Therefore, all C are mammals are B. felines.
  33. 33. Quick Application• All cats are animals. • Negative• Some pets are cats. conclusion from• Therefore, some affirmative premises pets are not (illicit affirmative) animals. • if A is a subset of B, and B is a subset of C, then A is not a subset of C.
  34. 34. Quick Application• Money is green • Fallacy of the• Trees are green, undistributed• money grows on middle trees. • All As are Cs. All Bs are Cs. • All A’s are B’s
  35. 35. Informal LogicAd HominemA personal attack: that is, an argumentbased on the perceived failings of anadversary rather than on the merits of thecase.Ad MisericordiamAn argument that involves an irrelevantor highly exaggerated appeal to pity orsympathy.BandwagonAn argument based on the assumptionthat the opinion of the majority is alwaysvalid: everyone believes it, so you shouldtoo.Begging the QuestionA fallacy in which the premise of anargument presupposes the truth of itsconclusion; in other words, the argumenttakes for granted what its supposed toprove. Also known as a circularargument.
  36. 36. Informal LogicDicto SimpliciterAn argument in which a general rule istreated as universally true regardless ofthe circumstances: a sweepinggeneralization.False DilemmaA fallacy of oversimplification: anargument in which only two alternativesare provided when in fact additionaloptions are available. Sometimes calledthe either-or fallacy.Name CallingA fallacy that relies on emotionallyloaded terms to influence an audience.Non SequiturAn argument in which a conclusion doesnot follow logically from what precededit.
  37. 37. Informal FallaciesPost HocA fallacy in which one event is said to bethe cause of a later event simplybecause it occurred earlier.Red HerringAn observation that draws attentionaway from the central issue in anargument or discussion.Stacking the DeckA fallacy in which any evidence thatsupports an opposing argument is simplyrejected, omitted, or ignored.Straw ManA fallacy in which an opponentsargument is overstated or misrepresentedin order to be more easily attacked orrefuted.
  38. 38. Activity 4:• In teams of 4 watch the following videos on your iPad by going to tctok.us• Identify the primary fallacy being used.• Explain why it is being used. Why is it effective?• Discuss how a topic could have been approached should the fallacy be corrected (avoid bias)
  39. 39. Blog 3: Logical Argument• Create a logical proposition with a formal or informal fallacy.• Respond to another student’s proposition with the correct identification. Offer a correction.
  40. 40. Blog 3: Logical Argument• Decide on a position that you care deeply about.• Find someone online (blogs, youtube, facebook, etc.) who you agree with on this position, but can see a logical fallacy in their presentation.• Write your position, their quote, and an analysis of the fallacy in one paragraph.
  41. 41. Thinker Portrait: Rene Descartes