Presentation on theme: "Criteria of Adequacy Testability Scope Fruitfulness Conservatism"— Presentation transcript:
1 Criteria of Adequacy Testability Scope Fruitfulness Conservatism Simplicity
2 What are their significance? Testability Necessary condition for being scientificPossible candidate for knowledgeMinimal condition for further studyScope, Fruitfulness, Conservatism, SimplicityInvolved in systematizing, unifying & developing scientific knowledge.
3 TestabilityA hypothesis is scientific only if it is testable, that is, only if it predicts something more than what is predicted by the background theory alone.E.g. what makes fluorescent lights work?The little fairy hypothesisNon-testable versionTestable versionAd hoc hypothesisA common type of non-testable hypotheses
4 ScopeOther things being equal, the best hypothesis is the one that has the greatest scope, that is, that explains and predicts successfully the most diverse phenomena.Einstein’s theory has greater scope than Newton’s.
6 FruitfulnessOther things being equal, the best hypothesis is the one that is the most fruitful, that is, makes the most successful novel predictions.Einstein’s theory’s novel prediction
7 ConservatismOther things being equal, the best hypothesis is the one that is the most conservative, that is, the one that fits best with established beliefs.E.g. hypothesis: a crime is committed by aliens.=?
8 SimplicityOther things being equal, the best hypothesis is the simplest one.Curve-fitting for experimental data:xyH1H2
9 The Copernican Revolution Ptolemy’s geocentric theory vs. Copernicus’s heliocentric theoryPtolemy(c )Copernicus( )
14 Retrograde motion in the Copernican system: The most influential factor:Copernicus’s theory is much simpler than Ptolemy’s theory!
15 Occam’s Razor Discussion: Do not multiply entities beyond necessity. Laplace ( ) & NapoleonDiscussion:There may have conflicts when applying the criteria.E.g., conflict between simplicity & conservatism in the case of Copernican vs. Ptolemaic theory.In which ways are Ptolemaic theory more conservative?William of Occam(c )
16 Suggestions for the paper, e.g. simplicity: How to measure simplicity?What is the cognitive status of simplicity?Is a simple theory closer to truth?Does it make sense to say so?What did A. N. Whitehead mean when he said, “Seek simplicity & distrust it”?And so on.
17 Further Example: Evolution vs. Creationism Charles Darwin
18 Testability & Conservatism EvolutionTestable claims, e.g.:About the fossil record of change in earlier speciesFits well with current established beliefs, e.g.:The Earth’s history is much longer than several thousands years.
19 Creationism Testable claims, e.g.: About the fossil recordConflicts with well-established beliefs, e.g.:Age of the universeBuoyancy of earlier speciesTypes of fossilNoah’s Ark and the great flood
20 Fruitfulness Evolution Creationism Has predicted novel facts, e.g.: Organisms should adapt to changing environments.Mechanisms for modifying features and passing them from generation to generation – genes and mutation!CreationismHas only made non-conservative novel claims, e.g. about buoyancy.
21 Simplicity Evolution Creationism Without postulating a supernatural being with supernatural powers, but natural mechanisms involved.CreationismPostulating a supernatural being with supernatural powers, but less natural mechanisms involved.Difficult to judge, but creationism seems to be simpler under “commonsense”.
22 Human arm bones (typical vertebrate pattern) ScopeEvolution explains diverse phenomena, e.g.:The fossil record of change in earlier speciesThe chemical and anatomical similarities of related life formsHuman arm bones (typical vertebrate pattern)DNA
23 The geographic distribution of related species E.g. the existence of Australia's, New Zealand's, and Hawaii's mostly unique biotic environments
24 Creationism’s scope is zero! Creationism’s explanations are either failed explanations (e.g. about the fossil record) or pseudo-explanations (偽贋說明).Pseudo-explanationAppealing to “an incomprehensible being with incomprehensible powers” – a notion that does not allow any predictions!Conclusion: It’s much much more reasonable to accept evolution than creationism.
25 Discussion: References Creationist: “A wing couldn’t have evolved gradually. What good is half a wing?”How would you reply if you’re a evolutionist?References