P160 Kuhn and his Critics

5,402 views

Published on

  • Be the first to comment

  • Be the first to like this

P160 Kuhn and his Critics

  1. 1. PHIL 160 "Kuhn and his Critics: Theory-laden Observations and the Question of Progress"
  2. 2. PHIL 160 LEARNING OBJECTIVES: PHIL 160 <ul><li>How are observations theory-laden? </li></ul><ul><li>What kind of progress can science make? </li></ul><ul><li>Responses to Kuhn’s account from Lakatos, Laudan, and Feyerabend. </li></ul>
  3. 3. PHIL 160 NORMAL SCIENCE Shared PARADIGM Puzzle-solving Solved puzzles CRISIS ANOMALIES Resistant Puzzles
  4. 4. Paradigm Comparison Shopping PHIL 160 Relative importance of : <ul><li>Unsolved puzzles? </li></ul><ul><li>Solved puzzles? </li></ul><ul><li>Fit with data? </li></ul><ul><li>Puzzle-solving power? </li></ul>Answers depend on which paradigm you’re in!
  5. 5. PHIL 160 Choice between paradigms subjective, not objective!
  6. 6. PHIL 160 Choose paradigm which best fits data Paradigm determines what the data are! Paradigm Comparison Shopping
  7. 7. Theory influences what you see! PHIL 160 Theory influences what you look for Observation is Theory-laden
  8. 8. PHIL 160 Don’t notice problem with card! Observation is Theory-laden Don’t expect black eight of hearts Theory of deck: ranks: 2-10, J, Q, K, A black suits: clubs, spades red suits: hearts, diamonds
  9. 9. PHIL 160 Inverting goggles experiment:
  10. 10. PHIL 160 What you’re looking at:
  11. 11. PHIL 160 What you see (wearing the goggles):
  12. 12. PHIL 160 But, after wearing the goggles long enough…
  13. 13. PHIL 160 … see the world right-side up again!
  14. 14. PHIL 160 Then, upon removing the goggles …
  15. 15. PHIL 160 Things look upside down again!
  16. 16. WORLD + SENSE ORGANS EXPERIENCE PHIL 160 Challenges our straightforward assumptions about observation:
  17. 17. SAME EXPERIENCE SAME STUFF IN WORLD + SAME SENSE ORGANS PHIL 160 Would be nice if we could be sure that
  18. 18. DIFFERENT STUFF IN WORLD PHIL 160 DIFFERENT EXPERIENCE + SAME SENSE ORGANS Would be nice if we could be sure that
  19. 19. WORLD-EXPERIENCE MATCH? Different sensory input from world, SAME EXPERIENCE . • Subject without goggles: tree right side up • Subject adjusted to goggles: tree right side up PHIL 160 Inverting goggles experiment makes us question one-to-one
  20. 20. PHIL 160 Same sensory input from world, DIFFERENT EXPERIENCE . WORLD-EXPERIENCE MATCH? • Subject without goggles: tree right side up • Subject adjusted to goggles who removes goggles: tree upside down Inverting goggles experiment makes us question one-to-one
  21. 21. PHIL 160 PHIL 160
  22. 22. PHIL 160 PHIL 160 Theory influences what I experience! Theory influences how I interpret what I experience Observation is Theory-laden
  23. 23. PHIL 160 WORLD + SENSE ORGANS + PARADIGM EXPERIENCE
  24. 24. PHIL 160 In Normal Science: more and more solved puzzles. Progress
  25. 25. PHIL 160 <ul><li>Truth? </li></ul><ul><li>Better predictions? </li></ul><ul><li>Better explanations? </li></ul>Science progresses toward what?
  26. 26. PHIL 160 Relative importance of: <ul><li>Unsolved puzzles? </li></ul><ul><li>Solved puzzles? </li></ul><ul><li>Fit with data? </li></ul><ul><li>Puzzle-solving power? </li></ul>Answers depend on which paradigm you’re in! Paradigm Comparison Shopping
  27. 27. PHIL 160 No paradigm-free way to get an objective comparison! Paradigm Comparison Shopping
  28. 28. PHIL 160 <ul><li>Value: </li></ul><ul><ul><li>Predictive accuracy </li></ul></ul><ul><ul><li>Consistency with other theories </li></ul></ul><ul><ul><li>Ability to unify phenomena </li></ul></ul><ul><ul><li>New ideas, discoveries </li></ul></ul>Constant features of science
  29. 29. PHIL 160 Across paradigms: no guarantee of getting closer to truth! Progress
  30. 30. PHIL 160 Progress Across paradigms: more puzzle-solving power?
  31. 31. PHIL 160 Doesn’t fit with the rest of Kuhn’s theory! Progress Across paradigms: more puzzle-solving power?
  32. 32. PHIL 160 Kuhn is right. So much for progress. Reaction:
  33. 33. PHIL 160 Kuhn is wrong. How does science make progress? How to counter claim that observations are theory-laden? Reaction:
  34. 34. PHIL 160 Scientists DON'T question paradigm Puzzle-solving NORMAL SCIENCE Shared PARADIGM
  35. 35. PHIL 160 REVOLUTION reject OLD PARADIGM Choice between paradigms SUBJECTIVE! adopt NEW PARADIGM
  36. 36. PHIL 160 Worries with Kuhn: Isn't science objective? Something wrong with Kuhn's account! Doesn't science make progress?
  37. 37. PHIL 160 Observation is Theory-laden Theory influences what I experience How could I use observations to test a theory?
  38. 38. PHIL 160 Lakatos Issue with Kuhn’s view: Makes scientific theory change rest on “mob psychology.” Scientific choices really come from rational competition!
  39. 39. PHIL 160 Lakatos Research program: Hard core (hypotheses that aren’t changed). Protective belt (auxiliary hypotheses, may be changed).
  40. 40. PHIL 160 Lakatos Rules for change within a research program: • No changes to hard core. • Changes to protective belt must be progressive (i.e., predict novel facts).
  41. 41. PHIL 160 Hard core (3 laws of motion, law of universal gravitation). Newtonian research program Protective belt (how many bodies, positions, masses, etc.).
  42. 42. PHIL 160 Don’t change hard core. Make progressive change to protective belt. Bad prediction of orbit of Uranus. Newtonian research program Progressive changes = predict novel facts (NOT just correcting a bad prediction)
  43. 43. PHIL 160 Hard core (as is). Protective belt (add a planet past Uranus). Newtonian research program
  44. 44. PHIL 160 • Now predicts orbit of Uranus accurately. • Predicts novel fact: existence of Neptune (confirmed by observation with telescope). Is this a good modification of the research program? Newtonian research program
  45. 45. PHIL 160 Lakatos Possible rule for choice between research programs: Always prefer progressive research programs to degenerating ones. But, Lakatos doesn’t impose this rule!
  46. 46. PHIL 160 • Don’t change hard core. • Change to protective belt: predict new planet (Vulcan). Bad prediction of orbit of Mercury. Newtonian research program
  47. 47. PHIL 160 Protective belt (add a planet between Sun and Mercury). Newtonian research program Hard core (as is).
  48. 48. PHIL 160 Newtonian research program • Now predicts orbit of Mercury accurately. Is this a good modification of the research program?
  49. 49. PHIL 160 • But, no novel facts (hypothesized planet Vulcan never observed). Newtonian research program • Now predicts orbit of Mercury accurately. Is this a good modification of the research program?
  50. 50. PHIL 160 Lakatos Possible rule for choice between research programs: Always prefer progressive research programs to degenerating ones. OK to keep degenerating research programs around awhile. Maybe they’ll become progressive later …
  51. 51. PHIL 160 Lakatos • Rational rules for modifying a research program. • No rational rules for choosing between research programs. So, doesn’t really make science more rational than Kuhn’s paradigm shifts!
  52. 52. PHIL 160 • Thinks Kuhn makes science look irrational. • “ Research traditions” (similar to research programs). Similar to Lakatos Laudan
  53. 53. PHIL 160 Research traditions: Hard core (occasionally modified) Protective belt (frequently modified) Laudan
  54. 54. PHIL 160 Acceptance - treat theory as true. Pursuit - explore consequences of theory (even if it seems unlikely to be true) Can accept one theory and pursue another! Laudan
  55. 55. PHIL 160 Laudan Accept theory with most puzzle-solving power to date. Pursue theory with best current rate of puzzle-solving. Rule for choice between research traditions:
  56. 56. PHIL 160 Makes sense of how we might accept a well-tested theory of bridge-building …
  57. 57. PHIL 160 … but also pursue a new, untested theory of bridge-building, to find out what we can do with it.
  58. 58. PHIL 160 Laudan Kuhn makes all normal science depend on believing the paradigm. Scientists can research theories without believing they are true!
  59. 59. PHIL 160 Normal science makes scientists look narrow-minded and dogmatic. Scientific work is creative ! Feyerabend Issue with Kuhn’s view:
  60. 60. PHIL 160 Anything goes! Science is an aspect of human creativity. Good scientists always think outside the box. Feyerabend
  61. 61. PHIL 160 Galileo’s thought experiment What do we expect if the Earth is stationary vs. orbiting the Sun?
  62. 62. PHIL 160 If Earth orbits Sun, expect cannonball to land far from base of tower.
  63. 63. PHIL 160 If Earth is stationary, expect cannonball to land at base of tower.
  64. 64. Galileo says: If Earth is orbiting the Sun, the cannonball also has a component of circular motion sweeping it along with the Earth. So, the cannonball would still land at the base of the tower, and the experiment cannot distinguish between a moving Earth and a stationary Earth!
  65. 65. PHIL 160 Rule: Theory should be responsive to observations and fit with common sense. Feyerabend Anything goes! Galileo’s achievement: abandoning this rule!
  66. 66. PHIL 160 <ul><li>Principle of tenacity: </li></ul><ul><ul><li>Keep theory around so it can be fully developed. </li></ul></ul>Feyerabend
  67. 67. <ul><li>Principle of proliferation: </li></ul><ul><ul><li>Develop multiple theories in any given field. </li></ul></ul>PHIL 160 Feyerabend
  68. 68. PHIL 160 • No selection mechanism or way to remove bad theories. • Lots of labor to fully develop so many theories. • Which theory gets used to solve practical problems? Feyerabend Feyerabend has no advice here!
  69. 69. PHIL 160 Science may be creative, but it’s not Art! Scientific theories need to fit with reality! Feyerabend
  70. 70. PHIL 160 Reaction: Lakatos and Laudan : Kuhn left out the rational rules; including rational rules ensures progress. Kuhn is right. So much for progress.
  71. 71. PHIL 160 Feyerabend : Rational rules are for sissies (and so is “normal science”). Reaction: Kuhn is right. So much for progress.
  72. 72. PHIL 160 Kuhn is wrong. How does science make progress? Reaction: (What’s a better description of science?)
  73. 73. PHIL 160 Point of philosophy of science? • Describe how science actually works and what it actually achieves? • Describe what science ought to do to be objective and make progress?

×