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Unit 2. The logic of scientific discovery
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Unit 2. The logic of scientific discovery

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Unit 2. The logic of scientific discovery [Philosophy of Science]

Unit 2. The logic of scientific discovery [Philosophy of Science]

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  • 1. Unit 2The logic of scientific discovery
  • 2. Demarcation
  • 3. Science and knowledge?
    What is the difference between science and pseudo-science?
    Scientists claim to increase our knowledge of the world
    But don’t astronomers and protagonists of intelligent design claim the same?
  • 4. demarcation
    What kind of theory, what kind of methodology, is useful and will advance humankind.
    This is called the demarcation problem.
  • 5. Back to epistemology
    Two main ideas about how to increase knowledge: empiricism and rationalism.
    Two related modern positions:
    logical positivism
    critical rationalism
  • 6. Logical Positivism
  • 7. Positivism
    positivism was developed by the 19th century philosopher and sociologist August Comte.
    Positivism is an epistemological perspective that holds that sense experience and positive verification are the only ways to get to authentic knowledge.
  • 8. Vienna circle and logical positivism
  • 9. Ludwig Wittgenstein (1889-1951)TractatusLogico-Philosophicus
  • 10.
  • 11. Whereof one cannot speak, thereof one must be silent.
  • 12.
  • 13. Analytic-synthetic (again)
    Synthetic: All men are arrogant
    Analytic: All men are human
    Analytic sentences and claims are empty, they are tautological
    Therefore only synthetic claims (induction) are scientific
  • 14.
  • 15. reductionism
    Every meaningful statement can be reduced to protocol sentences
    Protocol sentence: a sentence that describes immediate experience
  • 16. Confirmation and structure
    According to the verifiability principle a proposition is only "cognitively meaningful" if there is a procedure to determine whether it is true or false.
    The logical positivist tried to find logical patterns in experience, unobservable structures, laws, like the law of gravity.
  • 17. Logical positivism in short
    The analytic-synthetic distinction
    The verifiability theory of meaning
  • 18.
  • 19. The problem of induction
  • 20. We can verify (confirm) anything with everything
    Hypothesis (h): All ravens (F’s) are black (G)
    Every f we see that is g confirms h
    All F’s are G is logically equivalent to all nonblack things are not ravens.
    Following this logic: the observation of a white shoe also confirms the hypothesis
  • 21. Sir Karl Popper (1902-1994)
    critical rationalism
  • 22. Theory-ladenness of data
    A theory is like a flashlight
    Everything you shine on you see in the light of the flashlight.
    So confirmation as demarcation criterion won’t work.
  • 23. Einstein versus Marx
    Popper wanted to distinguish between real and pseudoscience
    Real science: Newton and Einstein
    Pseudoscience: Marx and Darwin
  • 24. Poppers demarcation criterion
    A theory is scientific if it is logically consistent.
    A theory is scientific if it is falsifiable.
  • 25. Falsification
  • 26. Falsification
    A theory is like a rule
    When falsified the rule is rejected (There are no ad hoc adjustments)
    Some statements are only falsifiable in theory, while others are even falsifiable in practice.
    The more risky a theory, the better the theory
  • 27. Marxism
    Marx called his ideas science
    Popper called the ideas of Marx pseudoscience
    Because uses ad hoc hypotheses
  • 28. Example
    One notices a white swan. From this one can conclude:
    At least one swan is white.
    From this, one may wish to conjecture:
    All swans are white.
    If we observe a black swan
    the theory is falsified.
  • 29. Problem solved?
    The big six:
    carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur
    Mono Lake: substitute phosphorus with arsenic